by sdougla2
A creature with a counterstrike, like the Darkfenne Hydra, can make a counterattack against every creature that attacks it in melee, including after it activates. On the other hand, I think you're overvaluing it.If you're going to swarm a Darkfenne Hydra with small melee creatures, you should incapacitate it first so that it can't make counterstrikes. There are plenty of ways to deal with it besides attacking it with small melee creatures though. As others have mentioned, ranged attacks are much better against it than weak melee attacks.
My first thought on dealing with the Darkfenne Hydra is honestly to get 3-4 armor, and ignore it. If I have 1 big creature or just a heavily equipped mage, I don't really care if my opponent has a Darkfenne Hydra wacking at me. If the damage is a problem, toss an Agony on it. If it's guarding, use Mongoose Agility to bypass it or just chuck it into a different zone with Force Push or Teleport. It's often not worth trying to kill it anyway. A control build can make it extremely ineffective, and an aggressive build can focus on killing the enemy mage before the Hydra does much. Swarms might have a bit more trouble with it due to it's ability to kill a level 1 creature per turn on average, but it's still extremely vulnerable to control.
Being slow is an enormous liability for a melee creature, and the Darkfenne Hydra needs offsetting advantages to make it worthwhile. Not to mention that Agony absolutely destroys it's offensive power.
In order to get much out of Darkfenne Hydra, you're going to need to commit to using Teleports and Force Pushes to maintain relevant positioning. Whether or not that's worthwhile depends on your strategy, but I doubt I'd take it with the Beastmaster, Forcemaster, Priestess, Warlock, or Warlord (12 points is a little steep). I'm not even sure I'd want it in most Wizard builds. I have 2 Wizards set up right now, and neither of them uses it, although one of them is well set up to take advantage, so I may end up adding it.
