This is just a random joke =v=~
The ownership of Pa Zai is in the hands of his mother Ye Hao Feiling, and he is currently making a guest appearance in the HP world.
Sai Zai himself is currently making a guest appearance in the HP world, but he is still acting as a mummy.
So this is really just a joke =v=
The embarrassing and inspiring daily life records of two big bosses (?) In the world of Faerûn who can destroy the world several times together...
PS: Never take it as a true story!
Regarding the story of Pa Zai and Sai Zai in the HP world, see "Atypical Time Travel: HP"