This is just in case someone is confused on Y/n's power.

. Y/n's power comes from soul absorption. When Y/n resisted the control with the help of Raiden, he absorbed the demon's soul

. the mental torture a .exe usually uses is something Y/n does not know how to do. Instead he accidentally uses it due to his own self loathing. 

. realm teleportation that in my canon is how .exe's  get between universes.  Is not completely in Y/n's control obviously. Y/n has to imagine the place before being able to go there.

. possession. Y/n could technically possess someone. But due to his trauma he would rather not. 

. reanimation. Y/n would rather not do this once agin due to his past trauma. 

Quick note. Y/n will not age due to, him being technically dead and the demons that create the .exe don't age.