She could just made mark younger. Eventually once they’ve both lived longer eve might decide to die with mark

I’ll go against the grain and say probably Mark. Given thousands, or tens of thousands, or hundreds of thousands of years, eventually something is likely to kill Eve completely and faster than she can activate her powers. She is by no means invulnerable (as seen by what happens to other Eve’s). A bullet to the head, a decapitation, an explosion, etc could all theoretically put her under.

She needs to be NEARLY dead in order to revive herself. Any quick, conclusive death would bypass that, and given enough time, I think that would likely happen eventually.

Mark, meanwhile, is likely to get even stronger over time. Not saying he couldn’t eventually bite it in combat or age (though we have no real way of knowing the Viltrumite lifespan since they seem to die ‘early’ in battle), just that I think Eve has tougher odds.