The buzz around D23 is building for a potentially big Avengers: Infinity War announcement, with Thanos’ assembled Infinity Gauntlet being the source.
The Infinity Gauntlet having the ability to manipulate realities could allow for a pre-existing, veteran Fantastic Four team to be brought in from a different universe to help defeat Thanos.
But, that will all change with Infinity War when he completely assembles the Infinity Gauntlet and unlocks its full power.
Thanos has so far unproven as an MCU big-bad, losing Infinity Stones rather than gaining them.