I think I've really narrowed down the main mechanics for a game I've been working on, but wanted some input before I started making it.

This is a turned-based top-down tactical game where the player controls a small party that fights incredibly over powered bosses. It's only boss fights, and each boss has its own mechanics and methods to defeat them, but I'm more focused on the player side of combat for this post.

The player performs different actions through the use of hanafuda-like cards loaded into a vertically scrolling timeline. Cards have warm-ups, cool-downs, and the actual move the card performs has its own length as well.

The player can perform variations of attacks, defenses, placing items, and moving across the battle-arena with these cards.

The two main elements to the combat system are card creation and turn prediction.

As the player progresses, they are given elements/mods and seals to create new cards for customized attacks.

Mods allow the player to modify a card and increase attack power/defense power/speed, and decrease cool down/warm up/energy use.

Seals are special items that grant a card specific abilities that can completely over-power a card.

To allow the player to have an abundance of mods to customize their cards while also dissuading them from immediately making OP cards, most mods will increase the energy cost to use.

The player's performance during a battle will decide how many mods they get. The player gets mods while fighting, but only gets to keep them if they win the battle. This encourages the player to go all out trying to be smart and land huge attacks to gain huge amounts of mods. Getting mods mid battle allows little shots of enjoyment and dopamine during battles instead of all at the end.

The player has a limit on how many cards they can have (haven't decided the limit yet), but can destroy old cards and get back some of the destroyed card's mods (not all mods are returned) and the card's seal.

As the player progresses, they can create cards for specific fights and really get creative with seals.

Seals can add unique OP alterations to cards (skipping all cool-downs warm-ups, allow a card to surpass set maximums for attack/defense/speed, prevent death when card in active use).

Seals are only obtained by completing optional challenges like defeating a boss in a single turn, sustaining no damage, only use one character in your party, etc.

The second main mechanic, turn prediction, allows the player to see a short preview of what MIGHT happen with the cards they have loaded up, before they commit to the turn.

This would add to the card mechanic in letting the player perfectly plan out every move of a strategy, allowing for unique bosses that require exact methods and plans to take down.

A couple simple ideas for bosses is one that's too fast and needs to be cornered by the party members, one that one hit kills the player requiring perfect evasion, one that duplicates and requires all copies to be killed in the same turn, one that tries to manipulate the player's movements to get characters into specific areas on the board for its attack, a snake like one that gets longer with each turn, some of these are a bit basic right now.

I feel like people who spend hours in a single battle in a tactical game would love what I'm trying to make here

What do y'all think?

Any improvements or suggestions?