I'm going to add another one to my list, My Soldier, and my Widow.
Want to feel like a robot mastermind that got sick of watching his minions fight for him, and decided to demonstrate why he's in charge of a robot army? Crab Spider is just for you.
Ever wonder what would happen if Sauron had a cloaking device, and his mace was not only poisoned, but could shoot poison-lasers? Bane spider is right up your alley!
Want to feel like there is absolutely nobody that can take you on in a one-on-one fight, and proceed to clear rooms with your insane defensive and offensive abilities and poisons? Night Widow.
Want to be slightly less effective at melee than the above, but be able to clear entire rooms with your psychic abilities, and be able to adapt to essentially any situation? Fortunata.