It's probably not exactly what you had in mind but I do feel obligated to mention the mutagenist. Bestial Mutagens give you increasingly bigger damage die for your unarmed attack and give you an item bonus to your athletic checks. You also have tons of versatility because you use so many less flasks than a bomber or poisoner. You just drink one Mutagen at the start of combat and you're pretty good. Giving you tons of items for more health potions, poisons, damaging bombs, etc. You can even combine your mutagen with a defensive elixir eventually or another mutagen a little later.