It's referencing a technique (「亜空間殺法」）of yelling to psyche oneself up and/or disturb the opponent, the flow, etc.
Idiot Realm Killer TechniqueMutual InterestNow that I've lost Nodo-chan to Saki-chan, the only one left for me to have exciting developments with is the club leader!Leader!AllianceThat flirt! She's not content with just us club members and is even going after Kazekoshi's captain...Leader!Captain!*sudden realization*
