The animation here may seem familiar to some of you, but the Mangekyou Sharingan is all new! So I figured I'd combine my two favorite things and not only reveal Rinji's redesigned (by me, in fact) and completely original Mangekyo Sharingan; but also have Rinji casting Amaterasu, which is cast from his right Mangekyo.
The virtually inextinguish black flames, created by this ability, manifest at the focal point of where the user is looking. Once the flames come into contact with the target, said target will continue to burn until reduced to ashes. It is possible to dodge Amaterasu, but it requires great speed and agility.
The downside to Rinji using Amaterasu, or any Mangekyo Sharingan ability for that matter, is the heavy strain it puts on the eyes. In the case of Amaterasu, that strain is especially apparent as you can see in this animation.
Anyway, thanks to Kiasha for making this! ^_^