After dealing with Thanos in Infinity War Pt.1 and Pt.2. Thanos with the gauntlet will bring most of the villains back from their own brinks of destruction and they will be a threat. But the whole MCU will be worried about the imminent threat of the big bad. There will probably be a Thunderbolts movie before the Avengers: Masters of Evil movie. That way the MCU will have their more supe'd up version of Suicide Squad. Maybe we can all hope for Fox to revert the FF right back to Disney... that way we get Kang, Annihilus, Galactus, Silver Surfer, and Doom but one can only hope. Silver Surfer, Beta Ray Bill, a reformed Ronan, Quasar, Ikon and you can put in Gladiator for the Annihilators. But not sure if Gladiator would be with X-Men universe or not.