Once you've completed the San Bakar's Trial quest and reached level 24 in Hogwarts Legacy, you'll be presented with the 39th main quest of the game, Wand Mastery. During the quest, Ollivander will hand you the newly crafted special wand, but Viktor Rookwood is there waiting for you to take it back from you.
While the quest may seem straightforward, defeating Rookwood won't be as easy. He was the leader of the faction that allied with Ranrok during the goblin rebellion, and he possesses powerful magical abilities that make him a tough opponent. However, let's focus on the right strategy and finish the quest quickly.
Consult With Gerbold Ollivander
To obtain a Keepers' wand, you visit Gerbold Ollivander's wand shop in Hogsmeade and inquire if he can create one using the artifacts you have gathered. A brief cutscene will then occur as Ollivander proceeds to craft the Keepers' wand for you. Once the wand is ready, you exit the shop and find Viktor Rookwood there waiting for you.
Upon encountering Viktor Rookwood, he presents an offer to join forces in order to prevent the Goblins from obtaining the final Repository from Ranrok. However, you decline his offer, and as a result, he teleports you to a battlefield where you will face various enemies, including Ashwinders. Your best strategy to defeat them is to keep moving to minimize the damage taken and to use Stupefy to eliminate them.
Defeat Viktor Rookwood
Soon after, Viktor will reappear and initiate a wand battle with you. To win the battle, press the indicated button on your screen as rapidly as possible to overpower him. Following a powerful blow dealt to Viktor, additional enemies will arrive on the scene. Quickly eliminate all of them, and you'll engage in several more wand battles with Viktor.
While the prospect of battling Viktor Rookwood may seem tough, it is not as challenging as it appears. With the right strategy, the fight can be resolved in mere minutes. A key tactic to take over him is to preserve the Ancient Magic as you engage in combat with the other Dark Wizards. Then, deploy it against Viktor to shatter his protective shield, allowing you to unleash your spells and deal a substantial amount of damage to him.
After defeating him, you will have saved your Keeper's Wand. Proceed to the Map Chamber and speak with Professor Fig regarding the events that have occurred.