Adamantium is a rare metal from Marvel Comics. The defining quality is that it is virtually indestructible, similar to Vibranium. Adamantium in Earth-199999 comes from Tiamut, first seen in Eternals which was put to sleep in the Indian Ocean.
The Time Variance Authority provide Deadpool with Adamantium katanas, along with a brand new suit to help them on their mission, which ultimately turned out to be the destruction of Earth-10005. Deadpool teams up with Wolverine and X-23, both of whom have Adamantium claws, and in Wolverine's case, his entire skeleton is surgically grafted with Adamantium.
