Chris Zylka as Eugene "Flash" Thompson
Seann William Scott as Wade "Deadpool" Wilson
Derek Luke as King T'Challa (Black Panther)
Dolph Lundgren as Kraven the Hunter (Ultimate Sabretooth)
Joseph Gilgun as Cletus "Carnage" Kassidy
Assuming he graduates from Midtown high school in TASM2, Eugene "Flash" Thompson (Chris Zylka) arranges plans for his summer vacation, but gets a phone call from his uncle Wade Wilson (Sean William Scott) asking him to fly out to Tangier, Morocco for the chance to become a well-paid mercenary working for King T’Challa of the African sovereign city-state Wakanda. Flash arrives at the 5-star luxury hotel his uncle could afford to stay at by working for an African king, and wants to bring home that kind of money to pay for his college tuition. He completes training exercises with Wade involving riot control of Arab Spring insurgents, and overthrowing computer-hacking regimes in under a month to become a full-fledged soldier of fortune. Flash designs his own black suit of ballistics armor with white spiderman-inspired lenses and a venom insignia spraypainted across the chest to distinguish himself from Wade’s red and black ninja outfit and twin FFV 890C combat rifles instead of katanas.
When a meteorite crashes in the Serengeti, King T’Challa Udaku (Black panther) sends his most powerful mercenaries (Flash, Deadpool, Luke Cage, Kasper Cole, Nezhno Abidemi) to retrieve any invaluable vibranium from the impact before resistance armies obtain it. He supplies his mercs with an antediluvian herbal supplement that augments strength, speed, stamina, and reflexes for the highest possible caliber of soldier.
I'm still working on the plot synopsis, but it's basically The Expendables with Marvel characters.