Amaterasu

Amaterasu is unique to the Uchiha clan. The jet-black flames are said to be as hot as the sun, and will burn for seven days and seven nights. Since the Mangekyo Sharingan is necessary to activate this jutsu, not many have learned it. All that is known is that it is very powerful since it can punch through a Mountain Toad's stomach which is, as stated by Jiraiya, fire retardant. Not surprisingly, it appears to use a large amount of chakra.
 * Name:
 * Type: Kekkei genkai, no rank, offensive
 * Users: Uchiha Itachi