[Snake]

Cannot reduce Schwarz Sturm - Guard, Struggle, Kick.
Reduces Sturm by 2 - Martial Artist (and Promotion) skills and spells. Movement. Racial skills and spells.
Resets Sturm to 0 - Anything else not listed.

Schwarz Sturm interacts with Ki Awoken, preventing the HP drain from happening but lowering its level by 1.

Backflip, Power Up and Aid interacts with Schwarz Sturm, granting +2 LVs instead of removing it.

Felsmanege interacts with Permafrost, creating Ice Points instead of Earth tiles.

Grandupper interacts with Ice Points, making it so if you fall down in an Ice Point you take 150% Ice ATK damage and get Frozen LV10 until your next round.

Geist Schritt is changed to have a 10 + (10 * Schwarz Sturm)% chance to trigger a Glancing Blow against the skill or spell targeting them, but costs 0M and has a 2 round cooldown.

Da dream, even if off-topic beyond the first part.