XCOM is a secret organisation designated in the defence against hostile extraterrestrial threats such as the Ethereals and defends Earth is humanity's first and last line of defence. There exists three different Vive'kijiik Universes two of which have slightly alternate differences expect that gene modifcations is not present in the first and neiter is the MEC suit, The last XCOM universe is an alternate scernario in which Xcom lost the invasion and is no more than a resistance cell and has access to the Spark unit.
XCOM unlike most other universe will use alien technology and extensively try reverse engineering no matter what and some of its soildershave psionics which makes the universes within XCOM each deadly in their own right.
The Multiverse War
Unkown amount of XCOM operatives
Unkown amount of Advent deserters
The original Xcom seires doesnt exist in the great multiverse wiki (until further notice)