The Alliance is a group formed by ARIA to stop Gargos' invasion on Earth. The Alliance is composed of former contestants of the Killer Instinct tournament and of Ultratech agents, later recruiting other members.
- ARIA (founder and leader)
- TJ Combo
- Kim Wu (recruited by Jago)
- Hisako / Shin Hisako (recruited by Kim Wu)
- Tusk (recruited by Kim Wu)
- Kilgore (reactivated & reprogrammed by ARIA)
- The members of the Alliance comprises of almost every playable fighter in Killer Instinct (2013), except for Sadira, the bonus characters Shadow Jago and Omen (for obvious reasons), the trio of guest fighters (Rash, Arbiter and General RAAM), Mira, Gargos (for obvious reasons), and Eyedol.
- Mira, under orders of The Coven, is feigning allegiance to Gargos, as her master is patiently waiting for the moment for the Astral tyrant to make a fatal mistake so that he may take his godlike powers and claim the Earth under his vampiric rule.
- While Omen (the playable one) still heeds his master's beck and call, he is constantly torn between utter loyalty to his Shadow Lord or acting on his own agenda, i.e., stealing Jago's body for himself and claiming the Earth as his own kingdom.
- It is currently unknown what Shadow Jago's intentions are and where his allegiance lies ever since Jago separated from Omen and came to exist as his own being.
- While Eyedol shares the Alliance's goal to defeat Gargos and his army of Omens, Mimics, and other creatures, he isn't a member of the Alliance, acting on his own accord.