Here is a also backstory of this character writen by a friend Jordan Morris:
Nageru - an alien mutant who, from a young age, generated the ability to grow razor edged shards from his body. These shards grew erratically from random areas of his body, eventually causing him to become blind and deaf. However, with every newly spawned shard, Nageru becomes more attuned with his sense of touch - able to "see" through vibrations in, not only solid objects, but the air itself. This innate ability of touch had another salvation - Nageru could use the protrusions from his body as projectiles. Pulling them from his skeleton caused great pain, but with every ejection, his accuracy became more attuned.
Nageru learned to separate pain from his other emotions so as to become a "perfect" master of his craft...but in doing so, he separated his conscience from his soul. Because of this reaction, his own body's subconscious, combined with his mutant abilities, grew a ring of solid bone that floated upon his crown, symbolizing the hole within his own soul. Whether it can ever be filled again is for Nageru to learn.
(Nageru means "throw" in Japanese)