Maybe Scythe is overpowered (considering he gets the same bonus that Killa does, but without any need for the wounds), but having a stronger dungeon doesn't always mean winning the game, so I think he is a good addition to the deck. Once your Boss deck is over 20 cards or so, I like having variety, so it doesn't really matter to me if he has a similar effect to another boss. If you're going for lots of bosses, grab this one, too!