She might appear prone to senseless charges, but Berserker was actually given a solid reason why she ought to aim at the Archer of Red. Just now, before Rider was hit in the shoulder by that arrow, Berserker was telepathically contacted.

'Listen carefully. I shall deal with the enemy's arrows as well as Rider. Make all due haste towards the opposing Archer.'

Berserker moaned in disagreement. That wouldn't work—nothing worked against Rider.

'My arrows will prove to be the exception. Confronting him directly may be somewhat beyond me—but please, place your trust in me.'

Berserker did not protest further. She had no choices left to begin with; for now, she might as well do as Archer said.

- Vol 1 Chapter 4