User blog comment:IamJakuhoRaikoben/Chapter 459 & 460: Weakness & The Alighted Pegasus, Review./@comment-5170433-20151102065341

I'm not sure if anyone else has had this theory but I'm pretty sure Brandish hid Alvarez's main army with her magic and they're just hiding somewhere (maybe in her coat like tiny fleas) and she'll unleash them when she's inside the guild. She's the Trojan horse.