This is during chapter 10, a what-if where Lancer takes almost a minute longer to kill Assassin in the Chamber of the Slate.
Lancer quickly dashed to the side of the redhead bleeding out on the floor of the Chamber of the Slate and placed his left hand on the man's biggest wound. With everything silent now, the demigod could hear the weak fluttering of his Master's heart. Sweat broke out across the Servant's forehead. Will he make it -
"Mikoto's red...It's going away..." Anna murmured. "But you'll bring it back, right Lancer?" A quick yelp from her when her left eye glowed.
Lancer couldn't find any words to say. The fluttering heartbeats ceased and Lancer could feel his mental link to Mikoto snap. His left hand was slowly pulled back and his head lowered, his expression unreadable.
"...Anna, close your eyes and don't open them until I say so."
Four Usagi tried to stop him as he approached, but he easily annihilated them in a vibrant display of scarlet. They were unable to slow him enough for two other Gold Clansmen to escort their King out. One tried to bash him with a staff but it was easily plucked out and jammed through the masked human's chest instead. The other found both his mask and his face ripped off. Daikaku could see the Red Servant's crimson eyes clearly. Cold, uncaring.
"I'm still really pissed that you not only had Anna kidnapped but you did that to Mikoto." As he turned to Daikaku, he couldn't help but tremble in fear. Killing intent came off the other man in waves. "You humans really are too frail. Your bodies break much easier than ours. Plus there's your internal organs." In a flash, Lancer's left hand plunged into the right side of Daikaku's chest and ripped out one of the old man's lungs. "For Heroic Spirits, our only vital organs are our heart and brain. Say we lose both of our lungs. Breathing isn't a requirement for us. So we won't get affected aside from having to endure the pain until they regenerate. But you humans are different. You're finding it hard to remain conscious, am I right?"
Gold aura exploded in Daikaku's right fist and it shot out at the Servant's face. But instead of dodging it, the smaller man caught the fist easily, no effort looking to be involved; he had reinforced his body with mana in his anger. "Ah, so you still have enough strength left to fight back? I'd normally be impressed and probably let you go to a hospital or something, but you killed my Master." Lancer's hold tightened and the fist was crushed like crushing an empty soda can. Despite the agony it causes, the Gold King managed to scream. "Don't think I'll show mercy." At those words, Lancer's left hand, which still held the fist, was pulled back. An explosion of blood and the old man's arm was ripped from its socket. "I'm not done venting."
Those strangled screams and the sound of flesh being torn made Anna peek her red eyes open. She couldn't hold back her gasp of horror at seeing the Red Servant brutally rip the man into bloody pieces until the screams went away, until the victim could hardly be identified anymore. Blood covered the demigod, but he didn't look to care in the slightest. He just gazed down at the fleshy chunks without any remorse or sympathy, the face of someone who isn't killing for fun but out of a personal obligation. Then he turned to the caged girl and walked over to her. She couldn't help but flinch back when he stood right before it.
"Anna, are you afraid of me now?"
Several seconds passed with no reply. Then Anna gulped and spoke up, her voice quiet like a whisper. "...No. Because you still have a beautiful red."
"Don't try lyin'. I can smell the fear on ya. It's okay. I'm still gonna get ya back in one piece." His spear materialized in his blood-covered left hand and he sliced the golden bars like a hot knife cutting butter. Anna nervously came out, continuing to gaze at the Servant.
"...How much longer do you have?"
"A couple hours. More if I'm lucky but I doubt it." He grinned and tried to add some lighthearted humor. "My Luck stat isn't great, after all."
"Can't you make a pact with anyone else in the Clan?"
"Now that I'm a Stray Servant someone in the area's gonna be chosen as a Master by the Grail. But if it isn't anyone in HOMRA then I can't."
"I'm the Lesser Grail, so maybe you can pact with me!"
"That might work if you had Command Seals. Ya could probably make artificial ones...dunno how long that'd take, though. I may be a lost cause...But you could be faced with an enormous burden as a result of havin' a Servant. Not to mention, your life will end up bein' targeted."
"I don't care! And maybe I can keep Mikoto's Command Seal from going to someone else and to me instead!"
"...We'll discuss it at the bar. I should get you both out. I'll carry Mikoto's body in one arm. I'll hold you in the other." He'd normally carry Mikoto's body in both arms to keep his injury elevated, but that's not needed now.
"But it looks like you can't use your right arm."
"That's an easy fix for me. Just some rune magecraft to reestablish the brain's electric signals to it with mana." His jacket materialized in his left hand. He used that and his teeth to tie the massive cut mostly closed. "I'll have slightly less time but I can carry ya both out." He gathered Mikoto in one arm then lifted Anna up it the other. She hugged the warrior's neck tightly, burying her face in his shoulder as he used a rune to blast a hole in the side of the Tower and escape.
- Dead end