Since Marvel Strike Force Mobile game came out of March 2018 years ago, this is going to be a perfect story and strategic game.
Those who don't know who is I'll explain.
Ultimus is a Kree/Eternal from the Kree homeworld Hala who appeared in the original comic 616 universe of 1974 issue Thor under the name of Demon Druid. In that issue, Thor's hammer bounced right off of him and he was able to knock Thor out in a single blow. In Marvel Strike Force Mobile game, Ultimus is a zealous and battle-scarred general and multiversal conqueror and at the head of a Kree war fleet who determined to secure the dominance of the Kree Empire once and for all.
That's why he would make a good fit for a marvel vs Capcom as the main antagonists alongside the Capcom villain as a partner and formed an alliance with Hydra, AIM, BioReign (from Bionic Commando), Shadaloo (from Street Fighter) and Umbrella Corporation (from Resident Evil). In order for an alliance and benefits for them to takeover the Multiverse under their control.