Michael a omnIversal being versus Thanos who is an entire universe and has control of himself.
I'm going with Michael for the 10/10, who's power is the infinite creation of all DC comics. Michael is one who created all of what you see on every page of every DC comic, the ink, the color, every molecule that makes up every character is from Michael. The infinite spark, the endless ocean with no shore.
Lucifer than used his will to shape all of that raw color, ink, penciling into the shapes we understand and recognize.
Okay. Before stating a winner we need to understand the weapon held by Thanos.
The HOTU is a weapon that allows its weilder to become everyone and anything in the "MULTIVERSE". It is considered the power of God, because it basically makes the owner be on top of the Power Hierchy! As seen in the comic, Thanos killed the LT who is second to TOAA. So it means that the HOTU grants it's weilder power over any being in the MULTIVERSE.
The HOTU acts as a server in a way, in where the algorithms of all the beings within the MULTIVERSE/UNIVERSE is written, and in where THANOS/WIELDER is able to interact/modify/erase these algorithms. Like we saw in the comic, Thanos became everyone (Interacted) in the Multiverse, then he could Erase them (Modify/Erase) including the LT.
Now this makes perfect sence. Since TOAA created the Multiverse, and along it the LT. This means again that the HOTU affects every MULTIVERSAL being e.g (LT, Cosmic beings, sentient life, etc). Any form of life that exists within the Universe.
Now going back to the main topic. We need to ask ourselves if Michael is a MULTIVERSAL being? The answer is no! If am not mistaken The Presence created Michael and Lucifer before the Multiverse and therefore in this case the HOTU would have no effect on these organisms. In the same way, when Thanos grabbed the HOTU, it doesn't mean that he had power over beings that existed before or away from the MULTIVERSE. For instance, the Beyonders, i believe weren't affected by the HOTU since they form no part of the multiverse. TOAA is another example, Thanos didn't became TOAA when he grabbed the Heart, since TOAA isn't a multiversal being. Any other form of life alien to the Multiverse wouldn't be affected by the HOTU. \
E.G. Thanos HOTU vs The Beyonders: Beyonders win, since they aren't affected by the Heart. So HOTU is useless in this battle.
In another thread (Thanos HOTU vs Superman Armor) then yes Thanos would win, since when merging both universes (MARVEL nad DC), superman would fall at a Universal scale, since he was born within the universe/mulltiverse, and then no matter his power level would be affected by the HOTU.
In conclusion, the HOTU is so powerful because if affects any form of life within the universe/multiverse, but by it's own way of working is useless against any being who doesn't belong to that Multiverse/Universe. Michael wins this one.
(This doesn't mean that Michael is more powerful than other beings the Heart of the Universe erased like the Living Tribunal, but only means that he isn't affected by the HOTU and therefore can win this one).
Anywho... Since this thread was made it has been revealed that a.) THOTI only represented a mere fraction of TOAA's powers, and b.) LT, like all other abstract beings in Marvel, is a universal entity.
Conversely, Michael's status/purpose/role has not changed: he still contains the totality of God's Demiurgic power... So take that for what it's worth. /shrug
You do know however that the Power of a "universal" Living Tribunal is the same of that of the Multiverses right? Doesn't matter, the LT's power is the same no matter where. LT is a multiversal being. No matter where, it is the same tribunal everywhere. Not as Eternity or other cosmic beings which change depending on the Universe.
Here I was all ready to say Thanos gets the shit slapped out of him and then I notice he has THOTU...
__________________ Chicken Boo, what's the matter with you? You don't act like the other chickens do. You wear a disguise to look like human guys, but you're not a man you're a Chicken Boo.
I think the Marvel Universe has changed since it became iteration 8 if Ultimates is anything to go by. It seems we have only one LT now and he is dead.
Michael wins easily even if thanos is completely scaled through all of Multiversal abstracts lvl .
Micheal alongside lucifer birthed the DC universe in to existence from void ( with abstracts such as endless being the side effect of them warping the creation ) .
They are even superior to endless parents like Night and Time who predates all versions of creations .
Dream plays similar role to Eternity ( since his death created a cosmic storm which would've erased all of realities in the DC ) and he was extremely terrfied of lucifer .
And you can even count the Source who is created alongside with the universe and whose powers greatly empowers all the cosmic entities in DC .
Swamp thing amped by the power of yggdrasil and green stomped a void embodiment pralaya who destroyed all of creation including spatial and temporal dimensions which is also a side effect of micheal and lucifer warping the creation .
So I think Micheal wins even if Thanos is completely scaled from abstracts . He can renew the gods creation by just existing and weilds the power of creating stuff from nothingness