Time Variant Assassin (Alternate MCU Story)

Attack

David woke up in a lab. He was on the ground with all his gear behind a wall of glass. "If i get tased one more time today, I'm gonna annihilate someone completely out of existence." David said to himself. He sat up and saw multiple people around him. "Hey! Hey! Get me out of here!" David said. He took a look around and started to realize it might be a Hydra Base. His mind went to one thing and he said it out loud. "Fuck Hydra." He said. A soldier looked over to him. "That get your attention? Now get me the fuck out of here or i swear to Christ, I'm gonna shove a shard of glass down your throat." David yelled at him. A Hydra soldier came up in his cell and grabbed his hair. David was pulled back and put on a bed. "Get away from me!" David shouted. The soldier held a knife above his head. David slashed his claw at the soldier's gut, making him groan in pain and let go of David. He rolled off the bed and grabbed the knife from the soldier. He stabbed it in his face, killing him. He saw he had an audience behind the glass. "Oh, you guys see me now? Good. Get me the fuck out of here!" David shouted. He pulled his knife out and stabbed the glass, breaking it. Some of the soldiers aimed their guns at David. David grabbed a fire extinguisher and strayed it at them, blocking their vision. He pulled his gun out and started shooting, killing five of them. The other ten soldiers tried shooting back. David ran at two of them and shoved his claws into their faces. He sliced downward, killing them both. David leaped on top of one and stabbed his claws in his eyes. He then flayed his face. David saw a chain and he wrapped it around one's neck. He pulled it and it brought them in the air. David then repeatedly shoved his claws in the soldier's gut, making his blood spray on him. Then he grabbed a glass shard and went to one and shoved the shard in his neck, then his eye. Five left. David jumped at one guy and started punching his face. He punched it until their face was a bloody pulp. One guy tried pulling David off, but David turned to them and kicked them in the head, killing them with the shoe knife. David then grabbed the dead man's head and tore it off. He used it as a weapon against the final three. He pummeled two of them with the head and killed them. The last Hydra soldier standing stood still while looking at David. David threw his knife at his head, killing him. He took it out of his skull and wiped the blade with his fingers like he was a Ghostface. "Done. I'm leaving." David said to himself. Then a wall blew up. A man in a blue suit and a red shield walked in. It was Captain America himself. "Don't shoot!" David yelled. He didn't do anything but look around the room at the corpses. "Captain Steve Rodgers, America's Hero, I'm David Demis." He said.
"Hello, David. Are you with Hydra?" Steve asked him.
"No. These piss ants kidnapped me. I killed them all." David said.
"Okay." Steve said.
"Honestly, I must admit it is an honor to meet you, Captain Rodgers." David said. Then he realized this is still 1942 and quickly changed the subject. "I'm not from here. I was sent to find you so I can... I don't know what I'm supposed to do with you." David said. Then more Hydra came. "Oh, gimme a fuckin break!" David exclaimed.
"Language." Steve said.
"Fuck language, America, let's put these guys down." David said. He reloaded his gun and shot three in the head. Steve threw his shield and it hit them. One ran at David with a taser. David took it, snapped it across his leg, and shoved it threw his head. "Dave!" Steve yelled. He tossed his shield to him. David caught it and blocked a guy behind him. He then slammed it into the soldier's head and then shot him. He gave the shield back to Steve and then grabbed a soldier's neck and sank his claws into it. David tore his throat out. "You're pretty violent." Captain America commented.
"No shit, thanks for the help." David responded. David ran at a guy and flayed his face, ending the second wave of Hydra soldiers. "Let's get out of here." Steve said.
"Right behind you, Cap." David said as he followed Steve out. One Hydra soldier tried sneaking behind David, but David did a backflip and handed his foot knife in his head.