His hand tightens on the Evoker. "No. I won't use it if you don't fucking touch me. And you are obsessed. You never leave me alone."

The way Maruki is always ready to shut him down when his thoughts are heading a direction Maruki doesn't like; the way Ren alone hasn't been actualized. The way the fate of the entire world was Ren's decision to begin with.

Maybe what's happening to Maruki's arm would disturb him more if it was happening to another person, but all Ren can see is that it's holding Maruki back, lessening the danger.