RPG Mode in GBVS uses a rather convoluted progression system for player equipment. Having played through it and found every weapon, I figured I'd make a guide that simply shows what grids a player can build. These grids are not necessarily optimal, but should be close. In most cases I've opted to the side of accessibility.

For the most part I'm going to leave out the theory as to why these grids use the exact combination of weapons they do. Largely speaking, it follows the same logic as grid building in the mobile game (mix multiple modifiers to avoid diminishing returns where possible). Some ratios of grid building for this game differ slightly to the mobile game due to only having a single, weaker aura.

Normal Mode - SR Grids

In normal mode, to save on resources, it's generally advised to simply build one grid and use it for everything. You'll gain most, if not all, of the resources required to do this during your playthrough without any excess grinding.

The fastest grid to build is Water, simply because you'll reach the water main boss first. If you intend to progress into Hard mode, it may be prudent to build a grid that's effective either against Water or Fire in order to more easily farm the early hard mode boss fights (water and fire being generally the most effective of the 4 core elements). This would mean either sticking to Water and having a harder time with the first main boss, or building Earth to have an easier time with that boss.

Luckily, the SR grids can be effectively bought from the shop if you don't want to grind fights for drops. Wherever reasonable, you should be using the uncap and skill upgrade functions to max out a weapon's capabilities. The shop SR weapons are slightly worse than farmable SR weapons dropped by bosses, but the difference is small enough to not worry over - the goal here is to beat normal mode without needing to stop and grind.

Water

• Main weapon: Leviathan Gaze Omega
  • Get 2 copies fom the first boss, one for completion, 1 for S rank. Use one to uncap the other.
• 5x Leviathan Gaze (SR)
  • Buy in shop
• 4x Ice Bow
  • Buy in shop
• If you receive a weapon with the Water Force aura as well as a damage-boosting skill from draw tickets, it can be an improvement to the main weapon slot.
• Other SSR weapons from draw tickets can be subbed over the equivalent weapon type (Leviathan to Leviathan, Non-Leviathan to Non-Leviathan) if they have Might skills and at least one uncap star.

Fire

• Main weapon: Colossus Cane Omega
  • Get 2 copies fom the second boss, one for completion, 1 for S rank. Use one to uncap the other.
• 5x Colossus Breaker
  • Buy in shop
• 4x Fragarach
  • Buy in shop
• If you receive a weapon with the Fire Force aura as well as a damage-boosting skill from draw tickets, it can be an improvement to the main weapon slot.
• Other SSR weapons from draw tickets can be subbed over the equivalent weapon type (Colossus to Colossus, Non-Colossus to Non-Colossus) if they have Might skills and at least one uncap star.

Earth

• Main weapon: Yggdrasil Crystal Blade Omega
  • Get 2 copies fom the third boss, one for completion, 1 for S rank. Use one to uncap the other.
• 5x Yggdrasil Bark
  • Buy in shop
• 4x Stiletto
  • Buy in shop
• If you receive a weapon with the Earth Force aura as well as a damage-boosting skill from draw tickets, it can be an improvement to the main weapon slot.
• Other SSR weapons from draw tickets can be subbed over the equivalent weapon type (Yggdrasil to Yggdrasil, Non-Yggdrasil to Non-Yggdrasil) if they have Might skills and at least one uncap star.

Wind

• Main weapon: Tiamat Gauntlet Omega
  • Get 2 copies fom the fourth boss, one for completion, 1 for S rank. Use one to uncap the other.
• 5x Tiamat Amood
  • Buy in shop.
• 4x Windrazer
  • Buy in shop
• If you receive a weapon with the Wind Force aura as well as a damage-boosting skill from draw tickets, it can be an improvement to the main weapon slot.
• Other SSR weapons from draw tickets can be subbed over the equivalent weapon type (Tiamat to Tiamat, Non-Tiamat to Non-Tiamat) if they have Might skills and at least one uncap star.

Dark and Light

These elements are impractical at this point in the game. Dark has no relevant bosses that would require elemental advantage until late in hard mode, and Light doesn't have the necessary weapons at SR to build a decent grid.

The dark grid can be built on the same logic as other grids (Omega mainhand, 5x Celeste weapons, 4x non-Celeste weapons). The light grid, however, only has one type of Might skill at SR (and no free SSR weapons at this point), and will get significantly worse results. You can just build a Light grid with 10x the SR Might weapon from the shop, but it shouldn't be necessary and may feel like a waste of resources later.

Need HP to clear a fight?

If you find yourself in need of HP, each element has HP-boosting SR and SSR weapons in the shop. While the SSR looks more tempting, if you're using the Omega weapon mainhand I'm recommending, the SR weapon with the matching first name and an HP skill will be multiplied by the mainhand. This makes it more effective as an HP boost, and also cheaper.

If you're swapping out weapons for HP, swap out one weapon of each type at a time to maintain a decent ratio.

Hard Mode - SSR Grids

After entering hard mode, you'll have reached the point where SSR weapons can be reliably farmed. For most grids, there are effectively 2 tiers of progression here (Light and Dark are again a lot of effort, but Light manages to be worth it this time around)

The tiers at SSR progression are effectively Dropped weapons, and Crafted weapons. For some slots, this is only a slight upgrade, in other slots, it's significant. Crafted weapons are obtained much more reliably, and you'll generally find you'll be able to make some before you've finished the collection of Dropped weapons from the same boss.

When upgrading from SR to SSR weapons, keep in mind that most SSR weapons are only better for damage if they've been uncapped to at least 1*. You can sell old weapons to reclaim not just the money spent on them, but also some of the skill shards and skill jewels used to upgrade their skills.

As with normal mode, you will likely only need one SSR grid to clear hard mode. Also, don't feel like you have to complete the entire grid - a skilled enough player can finish hard mode with just some minor upgrades/adjustments for HP over the SR grid, and just upgrading to 1* uncaps of the new weapons may be enough for the majority of players.

The Fire grid tends to give the most leeway for mistakes, but any grid works. Once a grid has reached about 40k HP, the AI will be able to complete most fights if given a healing skill (Regen 1 or 2 is recommended for this) so you can farm on auto.

Water - Very High ATK, Mid-High HP

• Main: Banana Bunch - Charlotta Hard Mode, S rank reward (One time only)
• 5x Fateless - Crafted, Ares Hard Raid materials
  • Filler: Leviathan Gaze Omega - Drop, Ares (Raid only)
  • Fateless is an upgrade at 2*
• 4x Any combination of the following:
  • Montague's Oath (Best HP) - Drop, Charlotta raid, rare
  • Murgleis (Best ATK) - Crafted, Katalina Hard materials
    • Filler: Vlisragna - Katalina drop
    • Murgleis is an upgrade at the same uncap level

Optimisation: You can farm Ares in the Tower of Babyl for more Banana Bunches. Replacing one Fateless with a fully uncapped Banana Bunch will result in slightly higher damage, but at a fairly significant HP loss.

Grand Order raid update

The new weapon "Cosmic Sword" which can be crafted with Grand Order raid materials offers a further optimisation on the Water grid, but only if the grid is mostly composed of Swords (Fateless and Murgleis).

• Main: Banana Bunch
• 4x Fateless
• 4x Murgleis
• Cosmic Sword - Crafted, Grand Order Hard materals

Fire - Very high HP, High ATK

• Main: Martial Steel of the Sovereign - Zeta Hard S rank reward (One time only)
• 5x Sol Remnant - Crafted, Colossus Hard Raid materials
  • Filler: Colossus Cane Omega - Drop, Colossus (Raid only)
  • Sol Remnant is an upgrade at 2* (possibly even 1*)
• 4x Lohengrin - Crafted, Percival hard materials
  • Filler: Dainsleif - Percival drop
  • Lohengrin is an upgrade at the same uncap level

Additional Martial Steel copies can be farmed from Colossus in the Tower of Babyl. At this point, it hasn't been tested if another copy in place of a Sol Remnant would be a damage upgrade.

Earth - High ATK, Mid-High HP

• Main: Drill - Ladiva Hard S rank reward (One time only)
• 5x Yggdrasil's Bough - Crafted, Yggdrasil Hard Raid materials
  • Filler: Yggdrasil Crystal Blade Omega - Drop, Yggdrasil (Raid only)
  • Yggdrasil's Bough is an upgrade at 2*
• 4x any combination of the following:
  • Thyrsus (Best HP) - Drop, Metera free quest VS Ladiva, rare
  • Venustas (Best damage) - Crafted, Narmaya hard materials
  • No filler weapons for these slots.

When using 4x Venustas, a second Drill doesn't improve damage further.

The Earth grid will appear to have lower ATK than Fire or Water, but compensates with a decent crit rate.

Grand Order raid update

Earth gets an almost entirely new grid with this update, base around the new weapons Perseus, Ancient Perseus, and Cosmic Harp.

• Main: Drill
• 4x Perseus - Drop, Grand Order (Hard)
• 4x Ancient Perseus - Drop, Grand Order (Hard)
• Cosmic Harp - Crafted, Grand Order (Hard) materials

This grid has higher HP and attack than the previous grids. In other words, a straight upgrade. However, the fight the weapons drop from is generally harder than the rest of the game.

Wind - Low-Mid ATK, Mid-High HP

• Main: Harp of Westerly Winds - Metera Hard S rank
• 5x Innocent Love - Crafted, Rose Queen Hard Raid materials
  • Filler: Tiamat Gauntlet Omega - Drop, Rose Queen (Raid only)
  • Innocent Love is an upgrade at 2*
• 4x any combination of the following:
  • Heiliges Schwert (New Best damage) - Drop,
  • Yyrkoon (Best damage) - Drop, Ladiva free quest VS Metera. Rare compared to the other weapons.
  • Tri-Bandia (Best HP) - Drop, Narmaya raid
  • Plume of Suparna (Middle ground) - Drop, Narmaya raid

Yyrkoon results in highest damage due to crit-stacking, again. The Wind grid will appear to have the lowest ATK, and is definitely weaker overall than the Earth grid.

Djeeta raid brought us a new weapon, Heiliges Schwert, which is basically Yyrkoon with Big ATK/Medium Crit instead of Medium ATK/Big Crit. This is a slight upgrade (ATK skills have a larger weight on damage than crit skills), and makes the grid stats look more comparable.

Farming the Narmaya raid weapons will have somewhat lower damage; in return, the HP is great.

Dark - High ATK, Low-Mid HP

• Main: Blade of the Scourged - Vaseraga Hard S rank reward (One time only)
• 5x Claw of Terror - Crafted, Bahamut Hard Raid materials
  • Filler: Celeste Zaghnal Omega - Drop, Bahamut
  • Claw of Terror is an upgrade at 2*
• 3x Ultima Knuckle - Crafted, Beelzebub Hard materials Bahamut Hard materials
• 1x Cosmic Gauntlet - Crafted, Beelzebub Hard materials
• Filler replacements for the Beelzebub weapons:
  • 2x Fudo-Kuniyuki - Drop, Lowain Hard or Beelzebub Hard
  • Sunspot Spear - Drop, Zeta Hard
  • Qilin Bow - Crafted, Metera Hard materials

Dark has the most varied grid at either tier, but if you want to build this, I must warn you that the grind for the Beelzebub weapons is immense, and the pay-off is currently quite low - the only Light bosses are Ferry (who you don't need to farm) and Gran (who you would probably farm to build a Light grid to make farming Beelzebub faster, not the other way around).

Without the Beelzebub weapons, the Dark grid is relatively weak in both damage and HP. The dropped weapons may still be a pain to farm.

Light - High HP, Absurd ATK

The Light grid has 3 stages instead of two. If you're not using the grid, you can skip straight straight to the last stage, as neither of the previous stages are farmed on the same bosses.

Filler stage:

• Mainhand: Harp of Dominion - Percival Hard S rank reward (One time only)
• 5x Luminiera Bolt Omega - Drop, Gran Hard
• 4x any of the following:
  • Ethereal Lasher - Crafted, Ferry Hard materials
  • Judgement Trickster - Crafted, Charlotta Hard materials
  • Huanglong Katana - Drop, Bahamut (Tower of Babyl)
  • Symbol of Justice - Drop, late Tower of Babyl
• More reasonably, you'll just farm nothing but Gran and slowly fill out the grid with Luminiera Sword Omega and Bolt Omega until you feel it's good enough. However, if you have these weapons from draw tickets, they'll work in the meantime.

Progression stage:

• Mainhand: Harp of Dominion - Percival Hard S rank reward (One time only)
• 9x Luminiera Sword Omega - Crafted, Gran Hard materials

End-game stage:

• Mainhand: Harp of Dominion - Percival Hard S rank reward (One time only)
• 9x Rhongomyniad - Crafted from Centrums. Centrums drop from the first 4 main bosses on Hard mode, including free quest versions. They don't drop in the Tower of Babyl.
  • Rhongomyniad is an upgrade to Luminiera Sword Omega at 2*.
  • A grid with just the Harp and a whole load of 0* Rhongomyniads may still be viable for most content

The Rhongomyniad grid has the absolute highest ATK stat of all grids possible in the game. More HP is possible but at that level unnecessary. The only real reason to farm this grid is to make Beelzebub as easy as possible to cut down on farming times for either his weapon skins or the dark grid - and it may be excessive, if you intend to farm him, start as soon as you feel comfortable.

The big pain of this grid is that it takes a long time to farm. However, farming it via the raid versions of each fight will also net you all the materials needed to make the first half of every other SSR grid except Dark.

Grand Order raid update

The Grand Order raid introduced cosmic weapons for every weapon type. These are efficient in grids with 8 or 9 weapons sharing the weapon type. When your grid is made up of Luminiera Swords, you can use Cosmic Sword. When it's made up of Rhongomyniads, you can use Cosmic Lance. These weapons replace the Harp of Dominion, reducing the grid's overall HP but improving ATK.

Niche Grids - Enmity

Enmity is a playstyle focused on taking weapons with skills named [prefix] Enmity. This skill gives a major increase to ATK, but comes with a requirement - the ATK boost only becomes active as the character loses HP. By playing through the Tower of Babyl, you can unlock two support skills which allow you to lower your own HP, enabling the damage aspect of these grids - these skills are Splitting Spirit, which trades 50% of your HP for a full SBA meter, and Conjunction, which reduces your HP to 1 and gives a short invulnerability period.

Currently, only Wind and Dark can build competent enmity grids, and they have very low base HP comparable to SR grids. Combined with the glass cannon playstyle means these are high risk, high reward grids.

Wind Enmity - Very High ATK, Low HP

• Main: Harp of Westerly Winds - Metera Hard S rank
• 5x Taimat Bolt Omega
• 4x Deidre's Claws
• All weapons drop from Rose Queen's raid on Hard, but are on the rarer side.

Dark Enmity - Very High ATK, Low HP

• Main: Blade of the Scourged - Vaseraga Hard S Rank
• 5x Celeste Claw Omega - Drops from Bahamut on Hard. Very rare.
• 3x Cute Ribbon - Drops from Beelzebub on Hard. Rare.
• 1x Cosmic Gauntlet - Crafted with materials from Hard Beelzebub.

Overall, the dark grid gets moderately better results than the wind grid, but the weapons are more annoying to acquire. Though you'd get them naturally if you tried to build the best possible standard Dark grid.

Grand Order raid update

Two more elements can build functional Enmity grids as of the Grand Order raid update.

In Fire, you can bring Ecke Sachs to replace Lohengrin, and Ancient Ecke Sachs to replace Sol Remnant. Both weapons drop in the Grand Order raid on Hard difficulty. This will only improve damage at low HP. Max HP will be lowered for each weapon replaced with the (Ancient) Ecke Sachs.

In Light, you can bring a mixture of Artemis and Ancient Artemis (4-5 of each). This will only improve damage at low HP, and has significantly low max HP - fix this with other weapons if you feel it's necessary.

Final Words

While completing every grid is a massive grind in this game, I just want to stress that it's reasonable to play through this game using one SR grid during normal mode (which may also be enough for most of hard mode), and an only half-complete SSR grid in hard mode. Many people who don't understand how grid building works or where to farm have ended up completing hard mode with significantly worse grids.

Building optimal here ends up being either a crutch for players that are struggling with fight mechanics, or just something for completionists to obsess over. Again, don't feel like you have to go all-in on SSR grid building before even trying to progress in hard mode.