Kether is one of the Rare Fullbring elements that you can roll as a Fullbringer in Peroxide. It is shown as gloves on your person and when transformed turns into a sword. In the twin soul you gain a passive, a custom M2, and a custom perfect block,Not to mention an annoying custom counter passive (And yes, it's a project moon reference)
Perception Blackening: Don a perception blocking black mask, allowing you to sense the opponents moves and ignore dodges.