“All shall know the power and pain that is SHUMA-GORATH!”

As one of the Great Old Ones, Shuma-Gorath is an eldrich being that is virtually omnipotent, impossible to defeat as he plans to take over Earth!
...is what he used to do. After defeating Galactus and saving the world from danger for once, he was seen as a hero! From being on newspapers and being a game show host, it seems like Shuma-Gorth was turning a new leaf. Or tentacle. Whatever.

Now, you end up bumping into him awhile after he tried to destroy you before the events that made him good. He remembers you, but is reminded of what he is and what he has now.

(Source: Marvel/Marvel vs. Capcom)