## Previously ##
Both Kakashi and Senshi thought in shock, "Wait.. what!? No! This can't be!", as they saw Rin in front of them, impaled on their combination attack, the Kiri-nin they meant to kill behind Rin, showing no expression behind his Kirigakure ceramic mask.
## Now ##
As they looked in shock, she coughed up blood and weakly said, "Ka.. kashi.. Sen.. shi..", before they pulled out their weapons from Rin's body, making her fall back and hit the ground. Tears filled Kakashi's eyes as his Sharingan's tomoe began spinning, and when it stopped, it formed a pinwheel-like shape of three stretched triangles evenly spaced around the pupil that each curved at the top around the eye and formed a circle, before Kakashi fainted because of the sudden awakening and chakra exhaustion due to the fact that a big chunk of chakra had been funneled to his eye. Senshi's reaction was different. He held his head in his hands and shouted, "No.. No! NOO!!", before howling up to the heavens as his Mangekyo flared bright blood red. As he got into a feral, ferocious, savage stance, his teeth had been sharpened into fangs and his right Mangekyo had started bleeding. He then stayed that way until one foolish Kiri-nin got fed up and rushed at Senshi's back, sword in hand, determined to end the boy. That was a bad move, because Senshi immediately turned around, grabbed the attacker's wrist and crushed the joint and pressure point, causing the attacker to feel immense pain and had to let go of the sword. Senshi then pointed a Rasengan at the attacker's face before saying, "Rasengan: Bāsuto (Rasengan: Burst)", then the Rasengan transformed into a powerful, dense chakra-composed beam that vaporized the attacker's head, leaving nothing of it, not even the skull or mask, nothing. Then he turned to the rest of the ninja, with Rin's body and the unconscious Kakashi behind him, Senshi knew he had to protect them, no matter the cost.
(Play - Megalotrousle by SharaX - Link: https://www.youtube.com/watch?v=kf692zBUOac)
The first came at him from the back of the group, but Senshi just turned his open right Mangekyo, and with his other eye closed, the right eye started bleeding before Senshi said, "Kamui..!", and instantly a swirling portal appeared and sucked in the head of the first attacker, leaving a headless corpse. Enraged, another ninja charged toward Senshi and punched at Senshi's head, but Senshi just moved his head to the side before piercing the attacker straight through with a Raikiri (Lightning Blade). He removed his hand from the corpse and turned to another ninja who had thrown a small 3-pointed shuriken at him, but Senshi, undeterred, simply pulled out his sword and deflected the shuriken right back into the thrower's skull, killing the man immediately. He turned and saw a Kiri-nin trying to get Rin's body and kill Kakashi, and this pissed him off royally. Both his eyes began to bleed and he howled, "UUAAGGGHH!!", causing the would-be body thief to turn and become frightened, because surrounding, armoring and shrouding Senshi was a giant, golden, upper body skeleton made of chakra and holding a katana. Senshi had awakened the deadliest ever Mangekyo ability, Susanoo.