Don't take them.
Whoops, I should introduce this section first. This is about the Daemon's unique HQ's (Changleing, Skulltaker, The Masque, Epidemius, The Blue Scribes and Karanak). Due to poor writing you can't take The Masque or The Blue Scribes as part of your 4 HQ limit. Most of these HQ's are cheaper (or the same price) except Karanak, who is no longer an upgrade for Hounds of Khorne? No idea why. He went from 50 (15 for Hound, 35 for Upgrade) points to 120. He's got a little more of everything though but is just not worth it in a shooting game. Let's get into why you should never take any of these guys (other than for cheesy cheese or fluffy armies)