Many of the monsters in that base have died. Some were tamed again after their previous tamers died because of the fight against the vampires.
As for the vampires, because everyone inside thinks that they are strong and very useful, they got tamed even though they needed to sacrifice some weaker mages for it.
There's only a few of the vampires left. And they finally realized that they are in a losing battle. Even though they have drunk a lot of blood and make them at their strongest form, they are not a match against a single master level mage.
But I never thought that the vampires are smart. Instead of just running away, they chose to only target the tamers to release their vampire friends. Once the vampires who were tamed freed, they escaped while also grabbing some humans with them. Probably so that they can drink their blood later on.