Blue Ritual is blacklist because despite being closed for nearly a year, they still have outstanding orders that are yet to be filled. They have also stolen designs, notably in Malus against Thunder, given that Thunder was a commission from them that was created before Malus and was then copied before it was released.
Twin Tail Creations is on the blacklist for theft, repeated use and defense of use of the r-slur, among other smaller issues. That post can be found here.