Aaron leapt backwards, trying to put some distance between him and this bear, but it lunged at him while he did so, tackling him to the ground. Aaron struggled underneath its weight, but he couldn't manage to lift it, nor even escape from its large frame.
The bear swung at him, using its sharp claws to leave deep cuts in his bones, but these didn't affect him since he had no nerves. Aaron threw punch after punch, but it was like hitting a brick wall. He wasn't getting anywhere, and the bear didn't even register that he HAD punched.
'Shit!' Aaron swore to himself, trying everything he could think of to get out. He grabbed his left arm and started using it as a child would a stick. He slapped the bear rapidly with it, only for the monster to bite straight through it. Aaron's left arm crumbled into a million pieces, instilling a true sense of fear into him.
The bear kept clawing at him, and all Aaron could do was try to block or deflect the attacks, but this bear had such a natural advantage that Aaron couldn't overcome it. His right arm followed his left, and soon the bear had its sights set on his ribs, praying something was inside. The damages went deeper and deeper, many of his bones being severed in half. If he were human, if he hadn't died from the blood loss, that bone damage would have been his guaranteed end.
He tried to use his legs to kick the bear off, but nothing happened. The bear kept attacking, but Aaron noticed that it was slowing down with the speed, and the strength of each hit was tailing off. Not long after, the bear fell deep into unconsciousness, and Aaron was trapped. He tried to kick the bear off again, but its weight was even more present since it was unconscious. All he could do was stay there until either it woke up and moved or someone else attacked it.
Aaron saw a glimmer of hope in a knife embedded in the bear's side. There was blood on it, but it had long since dried, meaning he couldn't hope for a human to find him.
He slowly shuffled his legs to the side of the bear, taking minutes to make even a centimetre of progress. However, anything at all was better than being trapped underneath this monster. He would have been screaming pain if he had any sense of touch or pain, but since he didn't, and couldn't feel fatigue due to having no muscles, Aaron's progress remained constant. Bit by bit, his legs got closer to the side of the bear, until, finally, his right leg got out, soon followed by his left. Using his newly-feed legs, Aaron started moving his torso by pushing against the bear, trying to get out of there as quickly as possible. After all, he was currently without his arms, so he was like a sitting duck to any monsters that could fight.
After around a minute of pushing against the bear, Aaron managed to pop his torso out from the bear's limp frame, and he would've breathed a sigh of relief if he could. He stared at the body of the bear, and quickly looked around, noticing no monsters in the area.
'it's my lucky day!' Aaron thought to himself, getting on his knees and using his mouth to pull out the knife. He was kind of expecting a window with all the information about the knife to pop up, like how it does when he gets a skill, but he had no such luck. Aaron looked down at the bear, and realised it wasn't breathing. It was dead.
Aaron took a look at the bear, and a thought crossed his mind. 'This thing won't miss its arms, right?'
Aaron, using the knife in his mouth, began making slow cuts into the flesh on the bear's left arm. He pushed through, and by sheer luck, managed to get through the monster's tough muscle before the blade snapped. As he made the final push, the blade broke at the top of the handle, but that didn't matter. Aaron laid down beside the now-severed left hand, and prayed for his idea to work.
Aaron was praying for [Separated Body] to recognise the bear's arm as his own. After all, he had cut it off, and by a pure technicality, he had won against it. Surely all the spoils of battle went to the winner, right? Aaron held his imaginary breath, and before long, the flesh from the bear's arm started to decompose, leaving an abnormally large skeletal arm in its place. He watched as it grafted itself to his body, almost as if an imaginary doctor was performing surgery on him. Soon, his arm was fully functional.
Now, it wasn't perfect, as it dragged along the floor when Aaron stood up, but it was a lot better than when he had none. He tested out his new limb, and the claws on it, by cutting into the other arm of the bear, and it went through as cleanly as butter. Not even three minutes later, Aaron had himself a pair of burly bear arms to his name.
Aaron made his way back over to his base, more accurately a hidey hole, and started wondering how he'd make room for himself with his new arms. Nothing came to his mind, so Aaron tried punching the wall. To his absolute shock, he created a large crack, and a subsequent hole, in the wall. 'Oh, I'm so glad I lost my old arms, they couldn't do THIS!' Aaron proclaimed with joy, at least to himself. 'Let's get this place set up.'
Aaron started punching deeper and deeper into the wall, until he was at least ten metres deep. He only went this far so that no monster without any purpose would walk too close to him when he wasn't concentrating. It also gave him a place to store any corpses in case they had any use to him.
Now, time to get started on the killing.