Though Professor Weasley takes the role of Hogwarts Legacy players' mentor (secondary to Professor Fig), she only directly teaches the player one spell. Transformation is a control spell that turns enemies, animals, and objects into something else entirely. At first, this may seem somewhat gimmicky, but it does have some useful applications. In order to learn this spell, players will need to progress far enough in the story to unlock Professor Weasley's Assignment and then complete said assignment and speak to the professor.
This is one of many spells that players learn by completing an assignment for a professor. Once players progress far enough in the story, they'll receive an owl from Professor Weasley explaining what it is they must do before they can learn the Transformation spell. After completing the assignment, Hogwarts Legacy players must head to the Transfiguration classroom and attend the class. The short cutscene will play, and players will then be given the opportunity to learn Transformation, the fourth and final control spell in the game.
Completing Professor Weasley's Assignment
Professor Weasley asks the player to hunt down two Field Guide pages before she will teach them the Transformation Spell. The first page is found in the Underground Harbor, and it's possible that players have already collected it. The second page is in the library, and obtaining it requires players to have started this assignment.
There are two main ways to get to the Underground Harbor, both of which start from the Viaduct Courtyard Floo Flame location. Fast travel there and head towards the statue of the werewolf in the courtyard. Next to this statue, there is a lift that will take players down into the Underground Harbor. Alternatively, players can simply ride their broom straight down the cliffside until they see an opening in the rocks at the water's surface. Swim through here to reach the Underground Harbor the same way first years would have when being ferried across the Black Lake.
For the second page, head to the library and find Sophronia Franklin. She reveals that she is reading the book that the player needs and will only give it to them if they answer her quiz. Thankfully, it doesn't matter if the player gets the questions right or wrong on this quiz, so players should simply do their best to answer Sophronia Franklin's quiz, and then she will place the book back on the pedestal. Use Revelio to obtain the Field Guide Page.
Learning Transformation
With both Field Guide pages, players should now head to Professor Weasley's Transfiguration classroom and attend the class.
After an entertaining scene, players will have the opportunity to learn Transformation and use it right then and there to turn a marble into a butterfly. Aim the cursor along the pattern shown on the screen and press the correct buttons at the correct times to learn the spell and add it to a space in one of the player's spell sets. This spell is now available for players to use as often as they like.
How to Use Transformation
In combat, Transformation will turn an enemy into an inanimate object like a barrel. While in this state, enemies obviously cannot attack the player in any way, and attacking them will simply cause them to revert to their original form. This spell is best used to remove enemies from combat temporarily while the player deals with other threats.
With a Talent Point spent on the spell, it can transform enemies into explosives, allowing them to be thrown at other enemies for devastating effect. Outside of combat, players can even make money using the Transformation spell by casting it on chickens, cows, and sheep.
Hogwarts Legacy is available now on PC, PS5, and Xbox Series X/S. PS4 and Xbox One ports are scheduled to release on April 4; the Nintendo Switch version is arriving on July 25, 2023.