There are 3 different factions in Modular Combat. Those factions are : Combine, Resistance and Aperture Science. This is a great feature that brings more fun than the other 2 factional games.
[Combine]
Leader : dARKWING
Members : Many
[Resistance]
Leader : XeZaM
Members : None
[Aperture Science]
Leader : DevilMarkes
Members : Dave
If you want to join a team, reply to this thread saying in what team you would like to be. Each faction/team has its own ways of rewarding its members. Also, each faction has its ranking list and system.