Thanos + Cube was a universal level threat. At that time, Cubes were among, if not the, most powerful items in the universe. Since then, they've been powered down to being "below" Celestials.
If this was the Cube that appeared in the original story, Thanos kills the entire gauntlet combined. As of now?
IMHO :
1) toss up
2) "wins" by BFR but Cube is burnt out (same thing as Classic Strange backed by the power of his artifacts and the Cube vs Set)
3) Demo wins if Classic version
4) Thanos wins
5) what's peak power Demo?
6) toss up
7) no clue what Ion is capable of
8) toss up
9) Thanos loses if we go by on panel statements
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I'm pretty sure cosmic cubes are stronger than cube beings. SO I believe he would stop at 9, but i'm not 100% sure of some of the power levels of the some of the people on this list.
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Peak Power Demo is probaly not entirely accurate; the most powerful version...the one who had eatten all the Hell Lords and all of Thors team...is who I am refering to here.
Demo by himself is just Demo who hasnt eatten any Gods...
It's hard, in general, to come up with concrete answers. The way power levels fluctuate throughout the years, it's really just best guesses and opinions.
For example :
A Cosmic Cube was drained dry merely BFRing Set from this universe and only then backed by the power of Classic Dr. Strange's artifacts (because when they were lost and his spell weaken, Set was free to contact Earth again). This happened 8 or so years after the story of Thanos using a Cube to basically make himself a universal threat.
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..even the outer hells are indifferent matters for they bow only to potent and archaic Nodens.
Zopzops arguments seem to be followin my train of thinking so I'll vote however he votes in this thread. :-P
Although I still think of the redskull/Korvac/captain America stirrings which showed how powerful a cube was....
But the recent starlord annihilation story arc didn't impress as much about a cubes over all levels.
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