If you were to make everyone immortal Eternity or Tribunal would step in due to imbalance. Brings too many outside forces into play that understand the natural order and the combination of those forces even the mortal ones would be enough to stop Phoenix. Forces would include every sorcerer from Strange to Doom. Most high level demons like Mephisto, who would suddenly be pissed due to the souls they would no longer be able to obtain. Just no feasible way Phoenix would be able to do that without other forces stepping in and saying No... GTFO. Even the phoenix has it's limits.
Dude they killed off Death and made everyone immortal in the "cancerverse" like Colossus said and no one did anything about it. Not the LT, not the Demon Lords, no one.
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..even the outer hells are indifferent matters for they bow only to potent and archaic Nodens.
true but in 616 generally if anything universe threatening happens LT and Eternity have a habit of stepping in whereas eternity analogues don't in other universes. I mean there have been several universes that have been utterly annihilated and LT has done nothing but in 616 there have been times when its only a galactic level threat at best and eternity has stepped in. 616 as the mainstream universe in Marvel has to keep going unlike spinoff universes so if the fight were to take place in the 616 universe than phoenix wouldn't be able to do it IMO and also cancerverse was loaded with PIS and low showings of characters who should have wiped the thing out before it ever became an issue. Galactus at the least should have UN the whole event and the watcher overseeing the damn thing could have stopped Sentry in the first place and stopped the whole thing before it ever happened but he didn't so meh. But in 616 universe I'm fairly certain that if the phoenix tried something like that she would be stopped by a host of characters and abstract level beings.
What does any of this have to do with a forum battle?
No one else is involved in such battles, its these characters in isolation from everything else. Just them, the environment and whatever resources it has in it. Thats that.
By your logic most forum battles waged would feature the police, intervening superhero teams, or SHIELD. Thats not how it works.
It's hard to gauge the power of the Endless because they don't have combative feats...but the implied power of Death is very, very large. And I'd say that Death of the Endless>>>>616 Marvel Death by a comfortable margin.
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"It is unwise to battle the Power Cosmic." - Silver Surfer