10 TRAGIC Predictions For Avengers 4
7. Thanos Revives The Dead To Torment The Survivors
One of the key revelations that came in the wake of Infinity War's release was the clarification of the powers of the Infinity Stones. According to that information, the Soul Stone has gthe ability to "control life and death" and that's an important distinction. It doesn't say that it has to power to kill: the inference of CONTROLLING both death AND life is far broader and it could well mean that Thanos could actually resurrect victims using the power.
We've already seen a running theme in the MCU of characters being haunted by ghosts from their pasts. In fact, it's almost a universally bonding characteristic of all of the Infinity War survivors. On top of that The Russos have openly clarified that each victim was chosen to have maximum dramatic impact on those left behind.
Adding those two together, it's not too much of a leap to suggest that Thanos may use these ghosts as weapons against his enemy, bringing back fallen friends under his control to challenge the survivors in a way we've never seen before. Well, aside from the whole Winter Soldier thing - but even that could be seen as foreshadowing to this. Just imagine Cap having to fight Bucky again, or Rocket having to battle Groot after they've just seen them killed again. Now that's drama!