shikaku kekkai genkai

The assassin's eye can only be activated after two days of extreme pain,
when active at stage one, the eyes of the user will turn a light grey and will allow the user thermal vision
at level two, the user's eyes will turn dark brown with markings around the edges, this stage will increase the user's speed by 30% and agility by 20%.
at stage three the eyes will turn grey again with red markings, this stage gives the user a 50% speed and agility boost, at this stage the user will be able to see people's heat signals thorugh solid matter.
at stage four the red markings will stay and the users eyes will turn pitch black, the speed, agility and strength will increase by a further 40%
at stage five the users eyes will turn similiar to the rin'negan, with red and black lines instead of violet and pink, this stage increases all of the users stats by a further 30%, the user will also grow giant bat wings, allowing for a slight flight ability, although it will only allow the user to hover the height of a house.

apporved.