[Snake]

Those are all Main Class-only skills.

Archer - Honed Barrage
On-Critical: Your next ranged Basic Attack within 3 rounds will gain different effects, based on the weapon type and/or sub-type.

Honed Barrage (Bows): The attack will gain 3 extra "rounds", similar to a handgun, inflict Flatfoot for 2 rounds, and target all enemies in a 2-wide circle area.
Honed Barrage (Handgun/Shotgun/Rifle): The attack will inflict Flatfoot for 2 rounds, and target all enemies in a 2-wide circle area.
Honed Barrage (Launcher): The attack will target all enemies in a 2-wide circle area and have a chance (25%) to destroy tiles in the area.

After the attack is done, you will dash 2 squares in the opposite direction you are facing.

Duelist - Fleur
Exists.

Rogue - Twin Dance
Exists.

Soldier - Controlled Aggression
On-Critical: If you have a Shield equipped, gain Controlled Aggression for 2 rounds, which interacts with Guard and Bash.

Controlled Aggression (Guard): When you use Guard, increases its LV by 2 and redirect non-bonus damage (once per unit) from allies within 3 range to yourself.
Controlled Aggression (Bash): When you use Bash, perform a Shield Bash, which can inflict Knockdown if your enemy is inflicted with movement-impairing effects, and deals blunt physical damage equal to (Shield UL + Scaled DEF + Soldier LV), that ignores protection and has Great Accuracy (forces a Glancing Blow that applies effects, if the enemy evades).

Martial Artist - Hustling Blitz
On-Critical: If Weathered Body is active, and if the attacking weapon is a Fist, gain Hustling Blitz for 2 rounds after the attack.

Hustling Blitz: Enables the Riposte from Duelist base class, and Twin Dance skill from the Rogue base class, even if you do not have them active. (They will be treated as max rank.)

Bard - Battle Rhythm
On-Critical: The next song or dance skill you use within 3 rounds will cost 0M and restore 10% FP of allies within 3 range.

From this point downwards I don't think these really NEED things like it, but could be funny to have them. Opinions are welcome.

Mage - Exploit Advantage
On-Critical: Refunds all of your Offensive spell Cooldowns. (I ran out of ideas, and critical hits/basic hits don't look like a mage's thing)

Curate - Harsh Lesson
On-Critical: Lowers the cooldown of Healing spells by 1 round. (Once per round) (I ran out of ideas, and critical hits/basic hits don't look like a curate's thing)

Summoner - Raise Morale
On-Critical: All summoned Youkai have their Move increased by 3, Evoke momentum costs reduced by 1, and FP costs reduced by 75%.

[renowner]

A lot of people main ghost MOSTLY just for Fleur. So giving rangers and such fleur-tier abilities without costing a class slot sounds like a pretty dangerous idea. That being said. . .

The archer stuff mostly seems fine. Even if archers are fucking GOATED right now. But flatfoot shouldn't be two rounds. The only class that inflicts it is soldier currently. Its a main class skill. And even IT only inflicts it for one round. (Until your next turn.) This should do the same, or not inflict flatfoot at all. Its already moving you away, which is pretty big.

Soldier shield version seems fine.
Soldier Bash version I think is very overpushed. Its a 1m skill that can then inflict knockdown and do severe protection ignoring damage. Costing the enemy 3m for 1m is stronger than fleur as-is. And then it does damage on top of that. If it made chargebash do this, that'd be a lot better. Or just have it raise your parry chance when you inflict a critical until your next turn. Both Demon hunter and Black Knight have parries, tactician is the only one who doesn't.

Hustling blitz i'm fine with, except the twin dance part. Fist weapons already double tap now. Riposte and Rogue's evasion passive is what i'd say is better. (The +5 evade that ignores the cap.)

Bard's is stronger than fleur and i'm completely against that one. Bard is also already extremely strong. A massive fp regen AND 0 momentum cost after you already crit? Way too pushed. Maybe only the FP thing and nothing tied to momentum would be fine.

Mage and curate: No.

SUmmoner: No. They 100% don't need this. If anything it should be a shapeshifter thing, they're the critical focused summoner promotion. They have bloody shift already however, which is already a main class only skill. No such thing is necessary.

I also still don't actually think this should even be done in general. . . Though the Martial Artist one is probably very good for the game, as currently there isn't much reason at all to main the class. The soldier one maybe, also. But black knights are already really deadly, crit a lot, have bonuses to crit, crit from 6 tiles away, and usually end up main classed. So i'm a little iffy on that one.

If it was changed to be a tactician thing, i'd love it. It feels more tactical anyway. Actually incentivizing tacticians to attack with basics and/or use shields.

[Snake]

All of those are main class-only skills so they don't stack with each other aside 80 APT memes.

Archer is a critical padding that only works with those weapons mentioned, mutated weapons should not apply, ideally.

Soldier (Bash) requires the enemy to be immobilized, slowed or clumsy to inflict knockdown (which is a status infliction chance), and requires a shield to be equipped, alongside needing to crit the enemy as a main class soldier.

Martial Artist's 'blitz' part comes from Twin Dance for fists, they may attack twice in 'attack damage instances', but not in 'amount of attacks done'. This was made envisioning to make the Martial Artist who is very limited into a certain equipment (due to Weathered Body's condition) set and weapon set, and duration set. The intent of this skill is to make a basic hitting Martial Artist glue to an enemy and as long as they're in melee range, they can overwhelm the enemy, but if the enemy breaks melee combat or disengages, they'll be forced to chase again and get lucky with another crit.

I'd think Bard's one is fine, since again, main class only, but by then onwards I ran out of genuine ideas, because none of the classes presented want to critically hit enemies. So the playstyle should be something new for each one of them.

[Raigen.Convict]

Summoner one is a buffed bloody shift from shapeshifter. Im down for making bloody shift better since shapeshifter is a bad attempt at a spelledge summoner. Works best as a magic with evokes.

[Ray2064]

If anything Hustling Blitz could certainly do with being less restrictive regarding weapon choice (You basically are forced into Fist/Fist. That and basic attacker MAs would most likely have Riposte due to having Ghost Main.) since MA is in dire need of any basic attacking support in general