[Snake]

Black Knight alone has 0 skills that inflict Knockdown.

Soldier has two, but they're too 'momentum wasteful' to be viable, but worth being Base Class tied.

-- Such as wasting 7M to inflict knockdown on Charge + Move + Turnover, the enemy will only lose 3M or 0M from Knockdown. Aside this being unusable with Swords or Axes, for being a Polearm skill.

-- The second is Charge + Bash + Flatfoot. This being wasteful because you need to waste 3 Skill Slots, and be melee in your turn for a better usage. When melee, it costs 2M for a 10-50% chance to inflict Knockdown. When not melee, you need to use 1M + 3M + 1M, so 5M to inflict Knockdown at a 10-50% chance. Aside this being restricted to Main Class only.

Black Knight won't get a big problem receiving this, to be honest. The 'buffed' Board Shaker will already have has it's restrictions tied to Armor type (Most of the BKs I see don't like using Heavy Armor and avoid using it like the plague, just because they don't have any worthy special effects or stat buffs tied to them), and at the same time, those people would be sacrificing their Armor of Eyes + Waraji combo to use a skill that can be resisted or ignored if someone hops over the user's torso weight.

And this would be an indirect buff to Dullahan, but they're really worth this buff, really. (Aside the fact the FP cost will stay the same, this might be even hurtful to them). And, the race is too hardcore to be played as anything else but Black Knight.