[quote=@Baklava]
Quick question~ in what sort of way would one become crippled after using 50% of your soul for a grudge?
[/quote]

Fine motor skills: Nil
Bodily constitution: Trash
General physical parameters: Around that of a five year old child, if that.

Also the mental issues, for instance one's capacity to form new memories will be shot, one's own name will sound like that of a stranger's, and so on. You're literally losing half of who "you" are so it's pretty bad.