This item drops from Houndmaster Kerrax located inside a cave at the Defiled Path in the Antoran Wastes. It also has a chance to be listed on the Black Market Auction House.
Here you can buy Vile Fiend for EU or US Servers.
You'll get guide for getting Vile Fiend
You'll be able to get Vile Fiend
Additional budget for Character transfer or Character boost to max level. BMAH Services in Shadowlands now requirement to have a max level character on server, so Trial character will not work.
Free time on evening, if you choose selfplay option