The memory-locking ability, while potent, has unintended side effects that drive the episode's second half:

Origami also undergoes a personality shift back to her "new timeline" persona, which remains unaffected by the memory seal. The "Kiss Contest" Date

The subconscious stress of losing Shido triggers Tohka’s "Inverse" form. Unlike her normal self, Tenka is aggressive and unimpressed by Mukuro’s manipulation.