Critical Impact (Fatal Mode) is a Command Style exclusive to Terra in Kingdom Hearts Birth by Sleep. It is activated by using basic Deck Commands, such as Quick Blitz and Stun Edge. It is similar to the circumstances in which Lexaeus powers up and becomes more powerful.
While using Critical Impact, Terra's attacks become much more powerful as each strike literally deals double damage as a second shock is tacked on to each strike. The finisher consists of Terra jumping in the air, and slamming to the ground, sending out a shockwave that damages all enemies within the radius.
When Terra is using Critical Impact, he gains a bright aura around him.