[Whether that's the truth or not there's no reason for Ryoji to doubt his words. Even though he's undoubtedly a villain, but that is just how he is: someone who cannot fathom the depths of despair one would feel in order to destroy literally everything there is.]

I'm not sure what kind of end would qualify as a "grandiose show stopper", but if that is your wish...When your time comes, I promise that I'll be for you.

[The words themselves are morbid enough, but coming from here it is said with altruistic sincerity.

Such a task is not so hard for an avatar of death, after all.]