Holocaust replaced Beak on the Exiles' team. His nationality comes from his father, Apocalypse -- his mother's lineage and his actual country of birth are not known.
All Age of Apocalypse appearances in chronological order :
X-Men Chronicles #1, 2
Age of Apocalypse One-shot #1(2)
Weapon X (1st series) #1
Astonishing X-Men (1st series) #2-4