Marvel: Infinite World-Hopping

I transmigrated into the Marvel Universe, only to be stomped to death by the Hulk on the very first day. What can the protagonist do when all he has is an immortal body?

Terrorists come to attack, but the protagonist has raised a whole swarm of little bugs that eat people without leaving a bone. What can he do?

The Chitauri invade, but humanity has help from Cybertron and a whole host of other aliens. What can they do?

Ultron threatens to send an army of Iron Men to wipe out humanity, but humanity has only an army of Terminators modified by Tony*. What can they do?

Thanos says he's going to kill me, but all I have are the Six Infinity Stones and a gauntlet. What can I do?

I'm the protagonist, and Marvel is a dangerous place. I'm freaking out right now.

This novel and its characters are purely fictional. Any resemblance to real people or events is purely coincidental. Do not imitate.