The Ikamuzu clan is one of the oldest clans in the leaf village they have a unique Kekkei Genkai and their secrets were wanted by every village in the world. The Ikamuzu clan was wiped out in the second ninja war and only has two remaining survivors one of whom is Oturan and the other is a rogue shinobi who is extremely powerful but rumored to have died in a fight with an unknown opponent after he went to get revenge on what happened to Oturan years ago. (The rogue shinobi was actually Ayiarij but that's a secret that died with the third hokage and that kid who killed him.But your not supposed to know that <.<)
The Ikamuzu weren't really respected in the leaf village because they were always drunk. The members were always drunk because from since birth their bodies are consumed with immense pain due to their kekkei genkei and alcohol was the only cure for that pain so they would always be drunk or spend years meditating to be one with pain or sum crap like that <_< .When the Ikamuzu clan were on the battle field everyone would be scared because of the powerful fire techniques they knew and the Kekkei Genkai they possessed.
The Uchiha clan and the Ikamuzu clan are said to be related cause of their use of fire Techniques.Their Kekkai Genkai is said to have a final form whereby the user is completely coveres in a black cloak that resembles the Flame Emperor and their Knowledge of Taijutsu,Genjutsu and Ninjutsu are increased and their usage of chakra is unlimited. But after using this technique known as The Soul flaming Conqueror they die after 15 minutes and in that last 15 minutes they feel no pain.
Oturan's father is said to have led the clan to it's demise for a reason that is still unknown Ayarji who was there said that Oturan's father wept bitterly before he died ....... Their history has been shrouded in secrecy for some reason and only Oroachimaru really knows their secret.... The name Ikamuzu is feared in every village,that's why Oturan rarely uses his last name. For some unknown reason the clan leader has a weird ability along with the Kekkei Genkai. But this ability is not a Kekkai Genkai it is something only the clan leaders are born with a special ability.
There was a ritual that was carried out by the Ikamuzu clan. The ritual was to seal the remains of the powerful Flame emperor inside the stomach of the clan leader's first born to maintain the dominance of their clan amongst others. A ritual that was banished by the Third Hokage during his first reign. The ritual was however carried on in secrecy by the elder men of the clan on Oturan Ikamuzu. This ritual was said to be the main cause of the assault on his people by the Clan Leader. The sealing was said to cause immense power in time of need the immense power of the emperor was said to be equal to the power of the sun but it's power usually caused damage to the vessel resulting in death by the age of 13. The age from which a Ikamuzu's power would begin to mature. The ritual was carried out on Oturan because it was said he had the same chakra and blood flow of the first clan member who was the only successful vessel for the Flame Emperor. The Emperor is a malicious and Vindictive spirit that only seeks to get revenge on the sage for defeating him eons ago. The history of the Flame Emperor is unknown.