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The Psycho Headbutt (サイコヘッドバット, Saiko Heddobatto) is one of Gill's special attacks.
Executed by performing a quarter-circle backward motion and pressing punch, the attack simply sees Gill hop and thrust his head down in a headbutting attack. The attack is mostly used as a part of a combo.  Urien possesses a functionally similar move, but uses charge motions and electrocutes instead.