In the Manga
The leader of the Chronos Numbers elite assassination squad Cerberus, in charge of the close-range attacks, Nizer wields a pair of tonfas named "Dioskuroi" which he wields with incredible skill, as he shows when he has to destroy a human turned into a werewolf through the Lucifer nanomachines, that can regenerate any part of its body as long as a single piece of it remains - He can even regenerate his head, causing Nizer to need to completely pulverize it. He holds a personal vendetta against Creed Diskenth for the death of Number X, his old partner Ash. He is unable to participate in the attack at Clarken Island due to grave injuries caused by Creed's Imagine Blade and a gunshot from Echidna.
In the Anime
In the attacks in the manga, Nizer suffers grave injuries and is unable to participate in the attack at Clarken Island. However, in the Anime the scene where Jenos reports the Kerberos mission results to Belze does not take place, therefore we might just speculate Nizer is in the same condition as in the manga. Also, in the Anime the scene where Creed kills Ash and injuries Nizer is shown, contrary to the manga where it is just mentioned.
Source: Wikipedia