For a bit of context for those not familiar with the character:

The guy doing the strangling, Add, kinda lost everything he had in his childhood due to war, including his freedom; in trying to escape, he fell into a timeless ruin where he was able to study and learn for ages and ages; one of the paths you can take as a player sets him on the path of trying to cook up a means to travel through time in an attempt to fix all that.

In advancing to the Diabolic Esper, you finally succeed! . . . But fail to get to the right timeline.
Add ends up in a timeline where nothing went wrong, where the Add of that past was having a perfectly happy childhood.
He tries again, and again, and again, and again, and again, and again, and with every retry, every new attempt, no matter how he recalculates, he invariably ends up back in that specific world where nothing went wrong, instead of his own past.

Eventually, weighed down by the futility of his efforts, something in Add's already unstable mind snaps.

And so here we are.