Popular mobile game “Contest of Champions,” created by Kabam, is celebrating its one-year anniversary with “Agents of S.H.I.E.L.D.” star Clark Gregg.

Kabam and Marvel have teamed up and launched a one-month in-game event featuring one of the Marvel Cinematic Universe’s linchpins. Beginning today and running for the next four weekz, “Contest of Champions” will feature a series of quests and battles with players’ teams fighting against a team of champions and bosses picked by Gregg.

Gregg, who plays Agent Phil Coulson in many Marvel movies as well as “S.H.I.E.L.D.,” chose S.H.I.E.L.D. agent and Avenger Black Widow, Avenger’s newcomer Vision, Heroes for Hire members Luke Cage and Iron Fist, and the cosmically-inclined Ms. Marvel. For his villains, Coulson chose from the top of the Marvel food chain: Ultron, Ronan the Accuser, Kang the Conqueror and the Mad Titan himself, Thanos.

“Contest of Champions” boasts a huge roster of characters from Marvel’s library including the Avengers, X-Men, Guardians of the Galaxy, Inhumans, Thunderbolts and more. The game was awarded the Editors’ Choice on the App Store when it was released and has been downloaded over 40 million times.