[Snake]

The field effect Earthbound Fog's Darkness damage, when resisted by an attacking enemy, lowers the Hexer's momentum by 1 at the start of their round.

This is a bug because such was changed a long time ago along with Raging Flame (from Lantern Bearer) to not affect the caster's Momentum anymore thanks to a Balance Fu, and somehow this weird interaction is back on this skill only.