The Hall of Herodiana side quest in Hogwarts Legacy becomes available during the main quest to Prepare for Your Search for the Final Keeper main chapter after completing a couple of the main quests. Travel to the Charms Classroom to find Sophronia Franklin nearby in the sitting area and speak with her. She’ll ask you to complete a series of Depulso trials to find Herodiana’s ensemble.
To start, head down to the first level of the Defense Against the Dark Arts Tower. Look on the southern side of the floor to find a wall with a switch on it. Cast Depulso on the switch to find the entrance to the Hall of Herodiana then head inside.
To solve the first puzzle, use Depulso to send the blocks to the east side of the room then climb up on the ledge and head through the door to find a chest containing the Herodiana’s Cape appearance.
For the second puzzle, you’ll need to combine the two groups of squares together and then move them to the southeastern corner of the room to reach the ledge leading to the next area. You’ll find a chest with Herodiana’s Attire along the way to the final challenge.
To solve the third puzzle, get the block into the position shown in the below image.
This will allow you to cross over to the cube ledge. You’ll then need to reset the puzzle allowing you to move the block to the other side of the cube ledge to reach the ledge at the end of the puzzle.
Pass through the door and loot the chest to receive Herodiana’s Cap. Return to Sophronia and speak with her while wearing the outfit to complete the quest.