Kusuna

was a shinobi who hailed from the Land of Demons.

Plot overview
Kusuna is Yomi's second in command of their team for their quest to destroy Shion and release the demon Mōryō. Before the mission began, Kusuna was infused with Yomi's dark medical ninjutsu so he could act as a catalyst for his team. After plowing through the temple's defenses, Kusuna and his team confront Shion, preparing to kill her but are stopped by Naruto. His sudden arrival and mass scale of Shadow Clones drive them back, until Kusuna orders Gitai, Setsuna, and Shizuku to use their multi-element combination to get rid of Naruto. After Neji, Sakura, and Lee show up to save Naruto, Kusuna has his team work up a diversion while he went after the running Shion.

Kusuna catches up to Shion, but before he can land the killing blow Neji grabs hold of him and blasts him into a wall. Seeing that the odds were against him and he didn't have an opening to replenish his team's chakra, Kusuna flees along with his team.

Later, after formulating a new strategy, Kusuna and his team attack again, working to separate Naruto and the others from Shion. As the plan seemingly worked from each of Shion's bodyguards being forced to fight separately, Kusuna goes chasing after Sakura who is holding Shion. Kusuna catches up to Sakura and incapacitates her before going after Shion. With his target now alone, Kusuna takes the opportunity to kill her, unaware that he actually killed Shion's bodyguard, Taruho, who disguised himself with a special transformation jutsu.

After learning from Yomi that Shion was still alive, they return to finish the job. While going out to find Shion and destroying the forest to do so, Neji correctly deduces that Kusuna is the reason for their opponents' unusually high prowess in multiple elements. After tricking Kusuna's team to use up their dark chakra, Neji ambushes Kusuna and unleashes his Eight Trigrams Sixty-Four Palms, taking away the enemy's main source of power and finishing off Kusuna.

Abilities
As a medical ninja, Kusuna's duty in battle is support. Unlike regular medical-nin, his primary goal is to enhance his team rather than heal them. He can also use his medical ninjutsu to effectively battle and kill his opponents.

He has shown to be a capable strategist, repeatedly being able to fool his enemies with various misdirections and combo attacks. Also being the second in command, Kusuna has also shown to be a capable leader and tactician. During the surprise attacks, he can quickly asses the situation at hand and effectively direct his team into a well-thought out counter-attack.