From Destinypedia, the Destiny wiki
Vex Sol Collective
Heroic Mercury Adventures Haunted Forest Verdant Forest
Summon Fallen High Durability Rapid Movement Fallen Melee Teleportation Arc Absorption shield Block Path
Irxahn, Proxy was a Vex simulation of a Fallen Captain seen in the Infinite Forest, where it acts as a Daemon firewall to inhibit any intruder attempting to progress through the Forest.