It’s an ability with cooldowns I think similar to class trait abilities. So what I did was use the formation editor to create a formation with my back row too far back in the initial fight to engage. Then I put a bait character (Cleric with ranged rod/wand for weapon) in between my front and back rows and usually they teleported to attack him. That gave my weak ranged guys time to then do some damage before the teleport ability reset for the shadows.

But even using this I still ended up constantly having to disengage my mage guy. Then I discovered the cleric spell that puts him into a bubble and after that things were a relative breeze. As soon as they mobbed my mage I used the bubble and all the shadows broke contact for other targets. Mage was out of the fight for a while but he stopped dying all the time when I used this method. Just make sure most of the shadows have teleported and used the ability before you fire off the spell.

My main is a Paladin, he and the fighter were my front rank. The cleric I bought and designed at the inn he was bait, and the mage was the elf in front of the inn who joined after the scripted fight, he was the back rank.

I have no doubt you wouldn't be complaining if it was an ability that your character was using lol.

You actually get the ability to teleport as well, eventually.

But, yeah, it is annoying for those shadows to just pop up next to your ranged characters. It was giving me quite a headache when i cleared out that Temple in Gilded Vale with just three characters: my PC (Cipher), elf wizard NPC you help out and that fighter NPC you get later. I'm purposely not recruiting or creating any characters from the inns.

Are a headache in the hardest setting, but men, those are smart shadows, they not only teleported to your rangers, but target first the most vulnerable!

After 2 encounters with them, I begin to cast protection in my wizard just to see how the shadows switched to my rouge NPC or the cleric if the rouge was already dead, and once the wizard protection ended...

P.d. Conclusion: I love those shadows !

I really like them ! I mean, it's a great example of how to make monsters harder without just pumping them with big stats, and force us to be creative and use new strategies. There are a lot of options in the fights, it's good we actually have to use them.

Even if they made me reload a few times to get there... :p

Well they are shadows of the dead priests you would expect them to be pretty clever in who they choose to attack.

I had to reload quite a few times in that temple. My main is a wizard, I have that elf wizard, and the fighter by the tree. So, 2 wizards and a fighter. Only 1 rest left once I cleared the hallway and had to deal with several rooms full of them.

The best strategy I found was to place my mages side by side about 5 feet or so back from the doorway (so the AoE range of fan of flames hit the doorway) and then sneak in the room with my fighter to activate all 4 or 5 shadows at once. Then run out and watch how fast they're moving towards the door to time my double cast of fan of flames just right. It usually would get all but one shadow, and then I would have to rely a little on luck and try to kill it before it took out my already-near-death elf mage.

And yeah, the teleporting sucks when you select both mages to start casting fan of flames, then you watch to your horror as most or all of the shadows teleport behind you just before the spells go off.

It's nice to see most people find them as irritating as I do.
It's nice I'll eventually have the teleport ability as well.
If it was a mage who'd used it to begin with, I'd not have complained; no mages I've seen even bother to move around much.

What I ended doing for the second region with shadow enemies (player fortress) is give every mage the +deflection spell, since I'm pretty sure shadow attacks are physical.
It's helped in a few areas since, where my group got mobbed, as well. :-)

Edit: The lighthouse is overrun with these shadows.
The biggest problem with them, aside from being fighters & mages in one, is that someone decided to use them like a mob unit.
In Baldur's Gate, for instance, goblins are numerous, because they are weak and easy to kill; shadows are being used in the same manner, but are MUCH harder to kill!