So many options for these teases.
Tease #1 could be: Toad, Angel, Vengeance, Maestro, Baron Strucker, Iron Lad, Patriot, Wiccan, Hulkling, Frankenstein, Werewolf by Night, Dracula, Zombie, Lady Deathstrike, Blackheart, Longshot, Falcon, Classic Luke Cage, Destroyer, Mandarin, and Jigsaw.
Tease #2 could be: Banshee, Xorn, Classic She-Hulk, Blob, Mole Man, Ronan the Accuser, Danger, Rachel Grey, Skaar, Doc Samson, Ka-Zar, Shanna, Zabu, Spiral, Kang the Conqueror, Tigra, Maria Hill, Dum Dum Dugan, Classic Valkyrie, Constrictor, Hope Summers, Ketch Ghost Rider, Viper, Daken, Thunderball, Piledriver, Madame Masque, US Agent, Ultron, Protector, Hyperion, Red She-Hulk, Ghost, Moonstone, Satana, and Wrecker
Tease #3 could be: A-Bomb, Death's Head, Thunderstrike, Korg, Triton, Yondu, Quasar, Mr. Negative, Collector, Karnak, Foolkiller, Slapstick, Solo, Executioner, Ragnarok, Championpool, Kidpool, Starfox, Death, Nebula, Cosmo the Dog, , Lockjaw, Moonboy, and Firestar
Tease #4: My money is on Crystal.
Also, that burnt Thanos arm looks like we might get a 4th Endgame wave. I'd go with Captain Marvel, Final Battle Thor, Nebula, Rocket Raccoon, Wong, Red Skull, and the Farmer Thanos BAF