B-Team Anti Mob Door?

Hey guys! im looking for a way to have an open door big enough for dragons while not allowing hostile mobs (or any other mob?) to get through.
I tried the Mob router but that has a 200 tick delay which allows many zombies through :I
Any suggestions?

 

Warded stones thaumcraft or maybe some guards

 

B team doesnt have Thaumcraft.
What do you mean by guards?

 

some melee turtles ?
ermmm
i am not sure i could help u more if u showed me a mod list[DOUBLEPOST=1459283536][/DOUBLEPOST]oh and maybe carpenters garage door ?

 

Im not actually playing the modpack anymore (it REALLY lacks content) But thanks for the attempted help