Animagus

Although Dumbledore said he would act according to Jon's arrangements, he still made the decisions on certain details himself.

After all, Jon knew little about how to guide a child into growing up smoothly, nor had he ever done it before.

Dumbledore excelled at teaching and nurturing people, so shaping Harry into the person they envisioned was something Dumbledore was good at.

Before the school term began, Jon made two trips to Grimmauld Place. Mrs. Black in the portrait was as noisy as ever, as though the peaceful conversation that had taken place in the room that night had merely been Jon's illusion. But Jon did not care much about it. He only made sure there were no major problems there before leaving.

Everything appeared steady and firmly under his control.

During this time, he was preparing to practice a spell.

Animagus.

This permanent transformation spell was somewhat difficult, but in Jon's current circumstances, there were no spells that were overly difficult—only conditions that were hard to fulfill.

He and Grindelwald examined the conditions required to cast the spell, and in the end, they concluded that it was unlikely to succeed. The essence of the spell was an alteration of one's bloodline, yet inside the body Jon had not only the bloodline of the Hufflepuff family, but also that of the Mysterious Bird from the East, which was, in essence, a living creature as well.

Still, there should have been some differences between mythical creatures and ordinary animals.

An Animagus could not use magic while transformed, but if a wizard was powerful and skilled enough, they could briefly shift forms, cast a spell, and then shift back—especially wandless wizards like Grindelwald and Jon.

Jon had mastered Transfiguration with great proficiency. Although he could not transform into another creature, Transfiguration combined