Because of his fate in this story which doesn't apply to Thanos in another story. It's like saying pretcon beyonder is more powerful than a character who comes like 40 years later who is more powerful. This is how I see it anyways.
I won't blame Marvel. Even if Jack Kirby came back from the dead and created a new character with Stan Lee called "The Indestructible Unkillable, Unkillable Thanos Killer" with the blessing of Joe Quesada, I know in my heart that Thanos could kill him and that he could not kill Thanos because Thanos is unkillable and he (Thanos) can kill unkillable characters, because Thanos is unkillable and can kill unkillable characters because he is Death's avatar. You don't think this? I've proven my point (see above) prove to me that this isn't so.
Because he was brought back into an indestructible form by Death. I also know where you are going with this so let's skip the foreplay and just get to the climax already.
Thanos just rejected death. Death has no jurisdiction over Mr. Immortal.
And I was searching for that maelstrom scan and it even said on something I stubbled across that in a upcoming comic "one of the GLA will die(except Mr. Immortal of course)"
__________________ Some men, just want to watch the world burn.
Where is it ever stated that the reason he can't die is because of his fate? He can't be killed because he is a Homo-Supreme. The only reason why he is destined to outlive the universe is because he can't die, and therefore that's the only possible way it could turn out.
You did nothing. She went in there and killed everyone. As easy as she could have killed thanos. As thanos is not near as unkillable as lobo much less Mr. Immortal who can't die period no matter who wants him dead.
__________________ Some men, just want to watch the world burn.
Thanos killed those in that realm whom he had no jurisdiction over which actually weakened him at first being there since he's the avatar of death and this universe was where life won.
I have proven my case and destroyed your jurisdiction argument.
He was granted the power to kill cancerverse beings by death. Death cannot grant thanos the power to kill Mr. immortal as she herself does not have the power.
Not really. Your just trolling and ignoring on panel proof.
__________________ Some men, just want to watch the world burn.