You technically can control the Thorms. As pointed out by SergeantCrwhips on the game’s subreddit, the Thorms don’t have immunity to the Control Undead spell. That means you can roll to control them if you’re a level higher than them.
Ketheric is level 11 so you must be max level to use the spell on him, which you won’t reach in Act 2. The others, however, are level eight, so you just have to wait until you’re level nine before facing them. “I also took advantage of this,” SPCNars14 commented.
Fights that start on ‘the other side of the door’ zone changes mean your group will start the fight at the proper location but Malus will stay in the same spot on the new ‘side of the door’ and not move at all. “Since you can’t directly control him, he will just stand completely still, that is until the person controlling him goes down. Once control is broken, he will immediately sprint into combat, but not to attack your enemies, instead he will attack you!
Super annoying, way more work than it’s worth, and overall a bad time.” If SPCNars14 hasn’t dissuaded you and you still want to try recruiting the three Thorms, you need to break your oath as a paladin. Doing so will transform the Channel Oath spell into Control Undead.
As SergeantCrwhips says, the easiest way to do this is to play as an Oath of Vengeance paladin and free Sazza from her prison cell in the Emerald Grove. Of course, it’s not just the Thorms you can rope into your service in Act 2. The_Shadow_Watches notes that you can use Control Undead on a spectator if you let the Shadowlands kill it.
That does mean you have to bring the flask from Act 1 with you, however. It’s a bit of a hassle, but having a spectator by your side as you fight your way through Shar’s cursed lands should make things a bit easier. The Thorms seem like they might be more trouble than they’re worth.
