Negation α

• Prereq: requires Core Earth

When an enemy attempts to spend a Possibility for an attribute or skill test, the Storm Knight may spend her own Possibility to instantly negate it. This is a free action she can perform as long as she’s aware of the rival’s action.

Negation may not be used to stop a foe from spending Possibilities to activate abilitise (such as Soak Damage).

Reality

Perhaps the most powerful of all the Storm Knights are those who can master reality. It is the raw stuff of the Possibility Wars, and with it, most anything can happen.

This perk leads to Extortionist, Nullify, Quash.
From Core Rules