Kurama

Kurama is first encountered in the series at the same time as Hiei. His ability is in manipulating plants, and he generally wields a whip created from a rose vine, complete with thorns. He is one of the wiser characters in the series and the smartest and calmest of the four main characters.
Kurama is generally regarded as the most calm and level-headed member of the group. His analytical nature is present in battle where he prefers to study the strengths and weaknesses of his opponents before devising a strategy of his own.
He is protective of those he cares about and is often merciless to anyone that poses them a threat, a shift in his usually friendly manner. In many instances, Kurama has shown to be very self-sacrificing in the interests of the safety of his friends and family.
Fox Demon Kurama/Yoko Kurama was a cold hearted and ruthless thief and the most feared bandit in Makai. He was considered to be an A-class demon (though he eventually surpasses that), and is said to be more than a thousand years old.
After being wounded by a bounty hunter while in his spirit fox form, Kurama sent his spirit into the Ningenkai (human world) where his spirit took refuge within an unborn child that had not yet gained a soul. It was from this point that Kurama made the transfer to a human body with the intention to recover his strength as the child developed. Kurama planned to leave Ningenkai to return to Makai after regaining his strength after an estimated ten years. However, sometime during or before the tenth year, an act of selflessness by his mother, Minamino Shiori, opened Kurama’s eyes to pain he had caused his mother while growing up. Thus, he decides to continue living his human life as Shiori’s son.
Kurama’s special ability is that he can turn plants into deadly weapons by manipulating his youki into that plant. Kurama has complete control over any Human Realm plant and has some control over Demon Realm plants. However Demon Fox Kurama has complete control over Demon Realm Plants and has more power than regular Kurama. The strength of Kurama’s moves depends on how much aura Kurama uses. He has an incredible sense of smell and he can read lips. Though Kurama is considered the second weakest of the four main fighters, topping out at low S-class power by the end of the series, he is easily the smartest fighter of the four. He relies on cunning and tactics and not necessarily power to win battles.