Nico is a very sickly individual who is dependent on medication for survival. While he initially hated medicine due to his phobia of the injections needed to take it, he is provided with oral medication in Nanba prison which causes him to greatly enjoy taking his medicine to the point of addiction.However, when it wears off, his cheerful persona disappears and is replaced with a violent, bloodthirsty personality. In this state, he refers to himself in the third person and becomes obsessed with retrieving his medicine, viewing it as his only lifeline.