Your knowledge of magic has advanced to the level of Dumbledore, Grindelwald, and Voldemort. Instead of simply having a base Hogwarts graduate level of knowledge about magic such as Potions, Charms, Dark arts, herbology, and more. You are now a veritable master in all fields of magic, being a genius on the level of Dumbledore, Grindelwald, and Voldemort when it comes to exploring magic and the effects of magic. You can come up with new uses of magic just by thinking about it and using your imagination to shape reality with your magic.
Instead of knowledge to create and enchant basic magical items, you have the talent of creating magical items beyond the scope of the original canon of Harry Potter, akin to Fanon/non-canon enchanters in Harry Potter.
You are now also able to use ancient magic. Magic that is beyond the scope of normal wizards has been all but forgotten by most modern wizards and witches. Just by possessing this magic, your powers in magic have been propelled to around five times greater levels, as well as being able to see magic and manipulate it to a greater degree than normal wizards.
Additionally, you can also optionally gain the knowledge and abilities of Voldemort, Grindelwald, and Dumbledore without the painful memories or the knowledge changing who you are as a person.