The Arms Alliance is the union and society between the planets of Cudgel, Pike, and Hatchet. Ages before EDEN made contact with NEUE, a number of Seldar's nobles and dissidents were exiled into the far reaches of space and the people settled onto the triumvirate of planets they discovered to be habitable. The capital planet of the Arms Alliance was Hatchet and were led by the Duke of Izayoi and his family. Beneath him were three representatives of the three planets known as the Three Marquis.
The area around the Arms Alliance planets were surrounded by a thick nebula that canceled all forms of communications and advanced functions on most ships. While not much else is revealed of the culture and society of the Arms Alliance, the architecture and clothing resemble that of traditional Japan. It is presumed that the Papillon Chaser was discovered in the system and the eldest daughter of the current Duke of Izayoi was discovered to be compatible with it. Knowing that their ancestry were forced into the frontier, many of the citizens of the Arms Alliance did not have favorable opinions on Seldar and those involved with them. An old Arms Alliance legend hinted involvement with the legendary planet of Sprite as well as certain involvement with the practice of magic.
Sometime before the events of MK, the Three Marquis were contacted by the emissary of Will, Parfait. The latter promised them technology of unprecedented capabilities and tasked them with proving themselves worthy of possessing it. The Three Marquis started acting independently of the Duke of Izayoi and planned to wage war against Seldar and its allied planets with assistance from Will technology. When the Will started actively operating in NEUE, the Arms Alliance did away with their grudges and made amends with Seldar and allied themselves to face the common threat.