Chainsaw Hand #Microfeats
The cruel fates that took your arm, gave you access to a replacement.
Prereq: Must have suffered a critical hit, and decided (as a player) that it disabled your arm, and played the character one arm down for an entire character level.
Benefit: You have a chainsaw (Tech Guide) as a hand. (Yes, even as a fantasy character.) You can use it as a one-handed weapon (dealing damage as if it was one size smaller), or two-handed, but you can’t use the arm with a chainsaw hand for anything else (including using a buckler) except reloading things that take two hands to reload (which you clutch to your chest with the chainsaw arm).
The chainsaw is as difficult to remove as a locked gauntlet. You are considered proficient with it as long as it’s attached to your arm. Pure luck provides you with one charge per day to recharge it. If your hand is ever restored or replaced by another option, cruel fate takes your chainsaw away, and this feat becomes Toughness or Iron Will.