I truly cannot fathom the logic in the developers' minds as they designed these enemies. The concept is fine- a buffed-up version of three already dangerous enemies, that has lots of health and can flee from combat so you need to find it repeatedly to whittle it down? Sure, I'm on board. But the action economy of these things is so absolutely abhorrent that it ruins any benefits this DLC can possibly offer. Even the most amateur of game master understands that there should never be any enemy that gets a full turn every single time the player does anything at all. Want to move three tiles? The Viper King gets a full turn to shake off the Stunned condition, move to you, and bind you. Try to enter Overwatch? The Behemoth Queen just thawed out, ran across the map to you, and stunned half your units with her slam attack. Curse out the developers for ever thinking these stupid things were a good idea? the Archon King just took to the skies and fired five bolts that'll come down on his next turn (and guess how long that will take! You got it- as long as it takes to move one unit out of the way. Sure hope you like one of your troops more than all of the others! )
These things are such a perfect example of why basic action economy is critical to a game that relies on turn-based combat like this, and I cannot for the life of me understand why developers who made a game that otherwise feels perfectly challenging while never stepping over into unfair could have missed the mark this badly. If you want the experience of having three unique, deadly, and intimidating monsters that pursue you through different battles, have powerful equipment rewards for beating them, and must be defeated multiple times before you satisfyingly finish them off for good, download the War of the Chosen DLC instead. If there's anything positive that can be said for Alien Hunters, it's that it potentially made WotC better by being a perfect example to the developers of what not to do.