Fume Release: Tobacco Guide

After performing the hand seals, Jakku releases a puff of green smoke from his mouth until the smoke takes a humanoite form like a ghost smoke. This ghost (aka Nicotine, or Nico, as Jakku calls) serves as storage for extra chakra that can meet Jakku's needs after he summon Nico.

Nicotine can also serve as a defender of Jakku, once he can release from his mouth green ash clouds that can block the enemy's view.

Once invoked, Nicotine wins personality and can interact with other people like a normal person (even being a smoke ghost). Jakku can break his connection with Nicotine without even making the invocation be undone. When released of the connection with Jakku, Nicotine can no longer provide chakra for Jakku and has a limited amount of it, though he can still throw ash clouds.