"Evan" is a clone of Apocalypse, created from blood samples from the previous child clone of En Sabah Nur who was killed in #4. He was artificially aged to 14 years old inside the World. He emerged and his new identities revealed in Uncanny X-Force (1st series) #18.
Evan is the clone of an Egyptian, born in the World, raised in a virtual American environment. His "Nationality" is therefore...an estimate.