Who is sending the letters (theory)

As the end of the episode "Enchanting Grom Fright" Luz's mother is seen getting multiple letters believing them to be sent from Luz herself. I have read and watched multiple theories about who could be sending the letters, that list includes: Eda, King, Amity, Willow, Gus, Lilith, or a character yet to be revealed. I believe it to be none of these, Amity, Willow, and Gus to are knowledge know nothing about Luz's mother or her address as well as having no motivation to do so. King knows too much about Luz (as bieng a good friend of hers) to Write the letters we see (they are really badly written, so bad that they spell Luz's name incorrectly) King also has no motivation to trick Luz's mother. Lilith has no knowledge about Luz or any reason to write letters, and Eda (the most believable) is a master trickster and witch, so I wouldnt believe she would write letters that obviously show it's not from Luz. I also sont believe that Dana would introduce such an important character in the second season. There is one character I believe would do it and have some motivation for doing so. I believe Emperor Belos/Kikimora wrote the letters. He for whatever reason has some reason to get to the human world and I believe he would want to make Luz's mother believe she is safe. He also would be the only one to have unnatural knowledge like knowing where she lives and who her mother is. He also clearly isnt human like (like the other witches) as seen by he blue eye, so he wouldn't be as skillful in writing as most would be. Either that or his servant Kikimora wrote them as she is shown as bieng not all that bright or powerful. Theres not too much information at the moment so I wont be surprised if I'm wrong but that the moment I believe it to be Emperor Belos, either him or Hooty.