A moyishuu is connected to a single dominant emotion that not only affects their personality, but also grants them a unique ability. The moyishuu can use this ability as a standard action, and they can’t use it again until they take a 10-minute rest to regain Stamina Points. The moyishuu chooses their soulfeel after taking a full night’s rest. Each soulfeel ability is a mind-affecting enchantment effect with a range of 30 feet. A successful Will saving throw negates the effect.

Much of the design of this pistol-like weapon is based off the biological systems of the disintegration lash class of Small Arm, though a caustoject's more traditional appearance is in stark contrast to its techno-organic inspiration. Caustojects create an injectable field that transforms ordinary matter into an acidic compound, disintegrating their targets from the inside. Syringes can be loaded into these weapons, allowing other materials to be quickly injected instead of an acidic discharge (in which case only the injection effect occurs'no acid damage is dealt).