In the beginning, yeah, you cannot do anything about it, later on, you can kill him before he kills your pets. Also, at this point in game, having pets can work against you.

95% of the game pets are useful. It's only the final boss that can kill them.

Bosses and even powerful non-bosses can also steal thorns or other auras, totally negating your Thorns warrior strategy. There are multiple hard-counters in the game if you try to always put your eggs in one basket. Same for pets.

pets on their own is stupid anyway.

an effect that just trigger on its own, independent from of the character, proc every turn, no set up needed, so stupid

consequently, any interaction with it, like the pet instakill is mind boggling stupid, as if the devs themself hate those pet mechanic, absolute failure in game design

No, many games have pets and the pets act on their own. You usually get bonus moves that you can cause the pet to do manually and from time to time, but pets aren't crazy, and having one boss in the game that negates pets isn't overkill.

Originally posted by el Darkness:

In the beginning, yeah, you cannot do anything about it, later on, you can kill him before he kills your pets. Also, at this point in game, having pets can work against you.

100% true on all points. It's a completely avoidable mechanic and even if it does trigger its not a big deal

Act 4 contains a lot of foes that will counter specific strategies (foes that purge thorns, a boss that will punish you for having too much block, foes that will wipe away your vitality, foes that punish you for stacking bless, etc.)
It's like that to prevent one-trick-ponies.

The boss killing your pets happens in round 3, but it is possible to defeat the boss before they get to take their turn during that round. Additionally, dead heroes cannot be targeted by this attack. Though I wouldn't recommend that as a strategy.

Pets are definitely worth having through the four acts of the game, and its only one-and-a-half fights where they're not present. Refusing to take them because they might not have 100% up-time doesn't make sense to me.
I guess the question that comes to mind is: which pet is so crucial to your build that you cannot substitite its effects via cards or equipment?

It's just not a fun interaction overall, there is very little counter play to it. It just kind of happens and it takes a chunk of fun away from your build.

For instance I dislike the damage scaled off Vanished cards, or current block value on the character. But there is much more straight forward counter play. You can be more conservative about using vanishing cards, or have cards in the deck that cashes out your block for damage.

Always has been incredibly stupid and I've called for it to be removed for ages now. Abruptly cutting a part of your kit out with no way to stop it beyond blitz the boss and kill them in 2 turns is incredibly stupid and has no place here. I'd also ignore the simps, they don't listen to reason and just make excuses for the poor balance decisions this developer makes time and time again. This game could be quite a bit better with some proper work put into it.

Obviously the solution is to make it random. He should wipe out a RANDOM equip slot, either across the whole party, or per character, instead of just always wiping your pet.

Originally posted by Drauka:

Obviously the solution is to make it random. He should wipe out a RANDOM equip slot, either across the whole party, or per character, instead of just always wiping your pet.

That would just create even more negative comments about this encounter after people have lost their most important gearpiece.
I do agree that players should have possibility to defend their pets (disregarding option to kill him before). Evasion? Buffer? Maybe if the Boss was weakened or frozen (which does nothing against bosses) he would have weaker effect?