I think it would go something like this:
*Doom is getting beaten up*
Luthor: Ha, my armor is far superior! You have no chance, you might as well give up!
Doom: Doubtful
*Ovoid Mind Transfer*
Luthor: WTF!? Well, at least I have your armor now and I can still fight
Doom: Oh really?
*Doom's armor self-destructs, with Luthor in it*