Info: Akuma-kun and Unico meet in the chapter titled ‘Hitoribocchi no Yuniko” (Lonely Unico) where Nishi Kaze (West Wind/Zephyrus) drops Unico off on a dark island. Akuma is on an empty and dark island living pretty much by himself. He never had any friends until Unico showed up.
The name Beezel is another name for Satan or Lucifer. Although in the first movie, Ghost Danshaku turns into Dai Akuma (AKA Great Devil or Satan… whatever ^^), Beezel is pretty much a regular demon/devil. In Japan, he is only known as Akuma or Akuma no Ko (Child of the Devil). Unico ends up calling him Akuma-kun which is why I tend to write that more than just Akuma.