In the Marvel universe there are many heroes. Some are Spider Man, Iron Man, The Hulk, Thor, Captain America, and others. The point is that there are many Marvel heroes and they will fight to the end.
There are also villains that are dran by evil and determend to destroy the world. Some villians are Loki, Venom, Carnage, Wiplash, Red Hulk, Red Skull, The Rino, Dr. Octopus, and others.
There are also anti heroes who are good and bad like Deadpool, Punisher, Wolvorine, and others. Most of them are for hire which means they do what they do for money. Most of the time some of these anti heroes are good guys.