Heroes:
* Avengers: Iron Man, Captain America, Thor, Hulk, Black Widow, Hawkeye, Scarlet Witch, Vision, War Machine, Spider-Man, Doctor Strange, Ant-Man, Wasp, Captain Marvel, Black Panther, Falcon, Winter Soldier, Ms. Marvel, She-Hulk, Hawkeye (Kate Bishop), Shang-Chi,
* X-Men: Professor X, Cyclops, Wolverine, Storm, Jean Grey, Beast, Rogue, Gambit, Nightcrawler, Colossus, Iceman, Emma Frost,
* Guardians of the Galaxy: Star-Lord, Gamora, Drax the Destroyer, Rocket Raccoon, Groot, Nebula, Mantis,
* Spider-Man Family: Spider-Man (Peter Parker), Miles Morales, Aunt May, Gwen Stacy, Mary Jane Watson, Eddie Brock, Venom, Green Goblin, Doctor Octopus,
* Other Heroes: Daredevil, Punisher, Luke Cage, Jessica Jones, Doctor Doom (depending on the story), Daredevil, Ghost Rider, Moon Knight,
* Marvel Cinematic Universe (MCU): The names of the characters listed above plus: WandaVision, Loki, Hawkeye (TV series), The Falcon and the Winter Soldier, Moon Knight, She-Hulk, Ms. Marvel,
* Recent Introductions: Kamala Khan (Ms. Marvel), Shang-Chi, Jane Foster (Thor), America Chavez,
Villains:
* Avengers Villains: Thanos, Loki, Red Skull, Ultron, Doctor Doom, Zemo, The Mandarin,
* X-Men Villains: Magneto, Apocalypse, Sabretooth, Mystique, Mr. Sinister,
* Spider-Man Villains: Green Goblin, Doctor Octopus, Venom, Carnage, Kraven the Hunter,
* Guardians of the Galaxy Villains: Ronan the Accuser, Thanos, Ego,
* Other Villains: Kingpin, Doctor Octopus, Green Goblin,
* Marvel Cinematic Universe (MCU): The names of the villains listed above plus: The Grandmaster, Hela, Dormammu,
This is just a small sampling of the vast array of Marvel characters. Let me know if you'd like to narrow down the list based on specific groups, powers, or even specific time periods!