Enryu's Thorn

The Thorn is a massive object found at the location where Enryu killed a Guardian. It was acquired by FUG, who found that it was "dead" and could not be used. The organization subsequently worked with the Workshop to try and find ways to create living Ignition Weapons so that the thorn could be implanted in a being and used. FUG's intention was to give the Thorn to their Slayer Candidate, Jyu Viole Grace to increase his power and aid him in killing Zahard. However, a faction within FUG decided that this was too risky, and planned to merge Viole into the thorn, activating it in a manner that would allow it to be used by anyone strong enough to wield it.

The Thorn was hidden within an aquatic arena being used for the Workshop Battle. In a turn of recent events the Thorn has been absorbed by Jyu Viole Grace. According to Hwa Ryun, the "fake thorn" given to Viole acted like a "bowl" for the real Thorn, allowing Viole to take the real Thorn within himself. It now hovers above Viole's right shoulder in a compressed form, similar to Horyang's wing.

It has also been called "The Real Thorn" and "The Thorn that could kill Kings".

Though it is called "Enryu's Thorn" but it's still unknown what it is. F.U.G. assumed it belongs to Enryu and that is what he used to kill the Guardian at 43rd floor. However, it is still unknown what it is and what it will become once activated.