Whats a good build that has Blood Warden and Noed in it

probably perks to force them to focus on gens or lose. like: discordance and pop.

Pig can be useful for this because you can put a trap on someone's head at one gen left, and then they can't leave until they've searched boxes. Knockout could help by making survivors not realize you're camping the slug, which is a big Bloodwarden giveaway. Maybe Rusty Attachments and Slow Release Toxin to slow down healing on your endgame hat survivor, and make them unable to Sprint Burst/Dead Hard away from you. I'm not sure about the last perk, maybe Deerstalker?

Also, it's imperative that you do not open the exit gates yourself. Doing that is a dead give away that you're running Bloodwarden. Instead you want to go to an exit that a survivor is currently at, get near enough to them to push them to open the gate, but then leave without pushing them outside the actual exit.