You gain access to the Resident Evil Tech tree. Not only can you make everything seen in the games and even movies if you desire, but you also can upgrade 21st century weapons like The Merchant, which also includes pushing a weapon past it's limit in one category like in the games. Due to also knowing the complete biology of every virus, parasite, and even the Megamycete you can recreate them, and with your extraordinary knowledge of biology, can even improve if not perfect them, so you can make your own Super Soldiers or your own personal B.O.W.S.
(Note: combining this with another Tinker power will let you also upgrade weapons in those tech trees).