Dr.Strange merged w/ Arioch vs In-Betweener

Okay, in this scenario Dr. Strange has magical artifacts from Cyttorak and Agamotto and is merged with the chaos lord Arioch. (This is the same setup he had against Shuma-Gorath in its realm). The chaos energy absorbed from Shuma is slowly but surely turning Strange/Arioch insane and the In-Betweener is sent to take him out. Can In-Betweener do it?

I thought Shuma Gorath was invincible in his own realm. If this Strange could beat him in his own realm then he's sure as hell going to be able to take In-Betweener.