This seems interesting, how about I tell some skill ideas?
Some of these are basically inspired by some SMT and Persona skills and abilities, so keep that in mind.
Counterstrike: Low percent chance to reflect the opponent’s attack to them (I’m not sure if there’s actually a skill that does something similar to this. If so, ignore this one).
Alley doctor: when healing an unit, there’s a chance that unit will additionally receive either a buff or debuff (like, gain +5 str that decreases each turn, or become poisoned).
Hero wannabe: When unit crits an enemy, that unit gain +3 points in STR and SPD.
Crippled determinator: at the cost of permanently having -5 SPD, the unit gains +3 in STR and DEF, and +4 in SKL.
Unfettered: Duplicates effective damage done to an enemy when it’s weak against certain weapons.
Ideal reality: may negate an attack or the use of a status staff. May also negate the use of staves like psychic and fortify.
Just die: magic percent chance to insta kill the enemy. The unit won’t spend any dark magic uses if using a dark tome.
Divine judgment: magic percent chance to insta kill the enemy. The unit won’t spend any light magic uses if using a light tome.
Treasure expert: the unit will obtain double the amount of an item dropped by defeating an enemy. (there’s the option to make certain items be dropped only once regardless if the unit has this skill)
Orgia mode: event based skill (like Gamble or Swap). Upon activating, the unit will become uncontrollable (like turning into a variant of a neutral ally) for three turns, but the unit gains a considerable amount of points in all its stats (like 3 or 5 points). Once three turns have passed, the unit will become controllable again, but they will lose 3 points in all their stats, each point decreasing each turn.
Kill stealing: if the unit gives the killing blow to an enemy that they didn’t attack before and was being attacked by someone else, they will gain double the experience.
Dreadful musician/singer/dancer: when using a dance skill, gives the danced unit +5 SPD, but also gives them -3 DEF and RES.
Tearjerking musician/singer/dancer: when using a dance skill, gives the danced unit +5 DEF/RES, but also gives them -2 SPD, -3 STR and -5 SKL.
Rain bringer: if unit is deployed, there’s a chance it will rain on the map.
Deadly upgrade: event based skill. Upon activating, the unit will heal all of its hp and gain +6 STR, SKL and SPD, at the cost of having -4 DEF and RES and being poisoned for the rest of the battle.
Great seal: event based skill. Insta kills the enemy at the cost of the unit’s life.