Kougenjin

Kougenjin (光幻刃) is the EX Skill that Zero obtains by defeating Sage Harpuia with an A or S rank in Mega Man Zero 2. With it, Zero releases a shockwave from the Z Saber.

Also, in Mega Man ZX, with Model OX in O.I.S (Overdrive Invoke System) mode, by holding down and pressing the main weapon button, you will do a thunder-element attack similar to Kougenjin.