Dark Seal activate: Dark Side

When enraged sayotsu's eyes turn red which is not sharingan this is his awakening of dark side which unleashes huge amount of chakra,sayotsu looses his mental state and begins to destroy every thing,his physical strength and speed increases drastically also his chakra reserves increases.In his state of dark side he looses control over himself he becomes like a tailed beast however once the darkside runs out it leaves sayotsu weakened.The advantage of dark side is genjutsu doesn't work on sayotsu when he is in his dark side state also his endurance increases beyond human limits. The Dark Side a seal is one of the strongest cursed seals. Similar to Sharingan, which, when activated,has red eyes and spread through out the user's body. Like all cursed seals, the user receives increased chakra levels and physical capabilities when the seal is active, to the point when only in first level Sayotsu had equal powers of Naruto in his two tailed form.

Sayotsu was branded with the cursed seal when he just went on his first mission as a chunin, which took place in the Land of grass.Sayotsu was kidnapped during the mission and was placed with the seal. In level one Sayotsu has equal powers with Naruto in his one tailed form while in his second state his power is equal to Naruto in his four-tailed form.

In level one,the user's physical appearance changes slightly ,his eyes grew red his skin darkens ,his nails and canine teeth grow longer and sharper. While in his second state a thick layer of skin totally covers his body resembling a small susanoo.