Hello! Your first paragraph says you recently transferred from WrA to MG – am I right in guessing that you meant to say you recently transferred from MG to WrA?
While I can think of a couple of guilds that might accommodate villainous characters, I don’t know of any that focus on villainhood as a central theme. This might be something to ask the people who organize the Horde Guild Faire. You can find a link to their Discord server in the thread for the most recent Faire here.