Real Name: Roberto DaCosta

Current Group Affiliation: Avengers

Former Group Affiliation: A.I.M., X-Men, New Mutants, Hellfire Club, X-Force, Mutant Liberation Front, X-Corporation, Fallen Angels, Bratpack, Gladiators

1st Appearance: MARVEL GRAPHIC NOVEL#4 (1982)

Issue Joined: AVENGERS(v.5)#1

Status: Eighty-fourth recruit, inactive member

Known Superhuman Powers: Citizen X can absorb solar energy for various purposes, including superhuman strength, endurance and concussive energy projection.

Other Aliases: Lord Imperial (II), Black King (V), Black Rook (III), Sunspot, Citizen V (VII)

Issues of Avengers featuring Citizen X:

VOL. 6: #690

(as Citizen V): VOL. 6: #675-677, #680-682, #684-685, #687-689; U.S. AVENGERS#12

(as Sunspot): VOL. 5: #1-6, #9, #14-24; AVENGERS A.I.#10; AVENGERS ASSEMBLE#18-19; AVENGERS WORLD#1, #9-10, #14, #17-20; CAPTAIN AMERICA & THE MIGHTY AVENGERS#9; NEW AVENGERS VOL. 4: #17; UNCANNY AVENGERS#11, #15

(as member of New Mutants): #299

(as Bobby DaCosta): VOL. 5: #11; AVENGERS WORLD#21; NEW AVENGERS VOL. 4: #1-6, #8-16, #18

(as Citizen V, member of A.I.M.): U.S.AVENGERS#1-11