The Cosmic Conglomerate

In reality, the only way Thanos with the Infinity Gauntlet can possibly be beaten in the MCU is through cosmic intervention. Even with a veritable army of heroes, the Avengers and their allies are unlikely to be able to scratch the Mad Titan when he’s wielding such immense power.

That being said, don’t expect all of the likes of Galactus, the Stranger, the Titan Kronos, Epoch, the entities Love and Hate, the Celestials, Master Order, Lord Chaos and Eternity to intervene in the fight. That kind of cosmic power and weirdness just wouldn’t fit in the MCU.

What you can probably expect are Celestials (they have been confirmed to have existed at some point in the MCU, when they were referred to as “ancient Celestial beings” in Guardians of the Galaxy, so having them reemerge to intervene in a cosmic battle of universal proportions makes sense) and possibly one or two more, but an army of cosmic beings isn’t likely (a proper depiction of Galactus would be awesome, however, and would be possible if the Fantastic Four and related characters were acquired by Marvel Studios).