[Snake]

My take on those suggestions:

Higanbana

Passive Skill

The Red Spider Lily technique, also known as 'Death by a Thousand Papercuts'. For every Kensei Combo you trigger, you gain or power up 'Higanbana' for 5 rounds. (Wazabane will not activate this.)

Higanbana Strike - Increases Critical and Critical Damage of your next, non-Wazabane basic attack by LV * 5. If the attack critically hits, it may inflict Lingering Damage (Slash) LV (Higanbana LV% of the target's max HP, max. LV = Kensei Class Level * 2) for LV * 2 rounds.

Tsubame-Gaeshi

Defensive Skill, 1+M

The swallow-cutter technique, which turns the enemy's momentum against themselves. On use, you'll enter a counter-attacking stance, increasing your Evade by 10 per momentum used. Every time you avoid an attack, you swiftly move to slash all other enemies within 5 Range of the attacker, dealing protection-ignoring bonus Slash damage equal to your bonus Evade.

Shunpo

Utility Skill, 2M, 3 round CD.

A honed version of the Martial Artist's flash-step technique. Target a location within 4 range and teleport towards it, facing the closest enemy. If the location you choose is adjacent to an enemy, the momentum is fully refunded.

Trickery: Gain Spirit Mirror for 1 round, if you do not have it active and are wearing Unarmored Torso.