My party are level 14 and we are running a high-level version of Tomb of Annihilation.
My players are now trying to break into Fane of the Night Serpent, the Yuan-Ti stronghold in Omu.
Based on lore,
The Yuan-Ti had superb intelligence compared to other races.
The yuan-ti took advantage of their great intelligence during battle, planning traps and making excellent use of their surroundings. They favored ambushes over direct attacks. If in groups, they sent their least valuable members forward first, meaning that purebloods advanced before halfbloods who advanced before abominations.
My party's current strategy is to go in through one of the entrances, kill a few enemies, and teleport out when things get hot. That is a strong counter to the ambusher-style combat of the Yuan-Ti. I'm not sure how the Yuan-Ti would handle this sort of repeated attack.
I'm looking for ways that have been previously described in lore about how the Yuan-Ti have defended their lairs against invaders. Even if not specifically described in lore, what specific abilities do the Yuan-Ti have, that could help in such situations, and how would they be efficiently deployed?