Yes, recruiting them with cheatengine. Wanted to see if there were any significant differences going on under the hood for some of these unique classes and surprisingly a good bit of them do have some interesting stipulations. Most npcs have all skills available, but some don't, and some are even uniquely curated and restricted for an npc unit. In pretty much every case, the unit cannot change class nor element.

Aym and Allocer - Possibly the best options for doing this, as they keep everything that makes them good in their fights. Allocer keeps her absurd range and damage shortbow, Aym's pebbles still hit like a truck and he keeps Petrifog (though it doesn't seem to have a proc rate above 0% any time I try). Can use any spell or skill per usual

Assassin Vyce: Strangely unique. Assassin has every generic NPC skill unlocked like most others, but he can only wield Daggers, Fists, Blowguns, Bows, and Crossbows. This is slightly different from Ranger who can wield 1h swords and axes on top of those options. He is also unable to equip spells - the way the limitations are all halfway there, it feels like they had a half baked/beta version of Ranger to use as an npc class.

Titan: These guys can use a checker board list of magic. Notably they can use elemental summons and healing magic but cant use AoEs unlike their Cyclops counterparts. Other than that, they get the same skills as normal cyclopses. They can use all missile spells, all summoning spells, boon, healing, ease/dispel, but not much else.

Onyx Dragon: While you only see these guys casting dark magic in game, they're actually capable of casting missile and aoes of other elements as well except divine. They can cast every dark spell except hellhound.

Crystal Dragon: They're divine dragons that can cast Healing, Exorcism, Awaken, Boon of Swiftness, Ease, Dispel, and Resurrect. In contrast to the Onyx dragon, they're restricted to divine magic and can't cast offensive spells.

Scylla / Naga: Unique in terms of NPC-only dragon classes as they don't actually get the poison breath weapon hydras usually get but have a choice of resonance skill and breath weapons from most elements. They seem like the only Dragon class that gets to choose their element skills liberally

Rukh - On top of the usual skills that Cockatrices have, they can use Vortex Breath and Wind Shot. They have access to all basic elemental missile spells and aoes (except apocrypha and draconic), including dark missile spells like drainheart.

Phoenix - Not that different from a Rukh. They get Flame Breath, Stun Breath, Wind Shot, Numbing Hook, Blood Siphon and the other usual griffin skills. They can only cast basic dark missile and aoe spells.

Dark Dorgalua (Phase 1 and 2) - Technically possible but softlocks the game, and wouldnt particularly be worth it even if it didn't. They lose their special skills, including Phase 2's Exaltio and Umbra. Phase 2 is also sorta broken as if you equip a counterattack weapon on him and he's prompted to counterattack, the game will softlock. There's probably SOME way of cheating out of the battle to not softlock, but I dunno what it is.

Knight Commanders (Coda 4) - They have all skills unlocked. Their magic is limited to missiles, aoes, and Heal 1-3. Most knight commanders lose what makes them unique after recruitment (they don't keep their unique finishers unfortunately) and like with most boss enemies they lose things like deathproof and fear immunity. Uniquely, they come with Gold versions of their weapons that seem to be a little weaker than their relic drop counterparts (probably to compensate the fact that these are given to level 70 units). Lanselot's Death Templar class is literally just a renaming of the knight commander class as it's functionally identical. Ozma doesn't use her player-accessible Knight Commander class, either, and like with other NPC Only classes they cannot be changed.

Wights - I always wanted one of these. They're exactly what they seem like when you fight them, terror knights that can use elemental aoes.

Rodrick - Nothing special here. All skills, all spells.

Heavenly Generals & Blackmoor - Recruitable, but nothing special. Blackmoor loses his Umbra skill after the battle, Heavenly Generals the same with their aoe skills. Death-Proof also goes away on recruitment. Uniquely with a "keep high level spell after recruit" cheat enabled, Blackmoor will keep Summon Darkness but will never be able to use it (Not that it works anyways, trying to use it with Nybeth just made it fail). Other than that, they are a generic all-skills-and-magic-unlocked npc unit.

Temple Guardians - I recruited Xolotl and the wind guardian. As they initially seem, theyre beast units with better base stats and the ability to cast apocrypha, though unlike other beast units that can cast spells, their spell list is totally untethered and they can cast any spell in the game including ninjutsu/war dances. Additionally, they have all skills unlocked, so you could load up a Xolotl with Howl or Petrification Breath if you wanted. (edited)

Hippogryph, Gorgon, Basilisk, Spriggan, Blood Gavial, every blue shaded potd unique - Not much to say compared to their contemporary counterparts; they just have higher base stats.

Rogue - I have never played the PSP version, so I don't know what the original class usually had. Rogues seem to only have Sparagmos, Speedster, No Knockback, and Fey Pact aside from the usual cut of skills. Interestingly, the PotD variants of rogues (Grim Reapers) only come with whatever skills they have equipped.

Templars - They are just reskins of other classes, as they seem. The only difference from other non-recruitables is that they can be renamed upon recruit, a detail they share with rogues.

Beelzebuth and Nybeth - they lose silence proof but otherwise are just necromancers.

Modiliani, Falfaday, Vepahl - Pretty much all the same class here. All skills and spells unlocked but they can only wield mage weapons like cudgels and their stats grow as mage units. Interestingly, Vepahl comes with Animate Dead equipped but she never uses it in her fights. Haven't tried recruiting falfaday but im pretty sure she's just a carbon copy of Vepahl

Xadoba - Loses her petrification eye skill that she never actually uses on recruit :(

The Hanged Man - All skills, no spells, surprisingly he can't use books, instruments, or fusils

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