Let's open the discussion to the first undead unit. Let us start with death Knights:
Executioner: I think this is not the strongest ability. It causes damage instead of retreat. Ok but lot of time i want to cause a retreat and the heroic-ability is quite useless. So I think Executioner is just a little Bonus, but nothing extraordinary. It has a synergy with Unholy Might: If you get the enemy unit weak thanks to executioner, you get a part of the retreat-Bonus back: they lose the counter!
Unholy Mitght: Unholy Might is an interesting ability that may keep you safe your Death Knight. The strong Basic attack of 4 and the several ways of Waiqar to cause "weakness" are making that ability quite powerfull. Being able to attack a blighted full-health unit with 4 dices and not getting any counter is what you want to do with them...
Hidden 3rd ability: FFG, we caught you tricking! What did they do? There is a difference between elite-melee and cavalry units: For the same Price, cavalry gets 1 skill Point more for free! I think the General idea was, that a skill-point on movement may be less important as Attack or Health. So they gave them a free skill on movement with the idea of giving the melee units better or defensiv abilities...
Now: The tricky designers create an cavalry unit with the movement skill (2) of a melee-unit to give them a free attack skill! They are the only non-legendary unit with a basic attack of 4 and movement 2 without any restrictions! So they have a powerfull hidden 3rd ability: add 1 dice to your Basic attack skill of 3!
My opinion:
For the mentioned reason I think that this unit with one relativ weak ability like executioner is a good unit. Look at them as an elite-melee unit with better skills than any other elite melee and one quite weak and one quite good ability.
What is the duty of death Knights? A massive offensiv threat with a good defensiv ability. A unit to knock out your enemies at the same time as you might get a defensiv boost when you cause blightness. So archers and dragon are it's best friends. So they are representing one of the 2 general ways to play Waiqar: Not the Necromancer / Minion-Support tactic but the Dragon-Archers-Knights-blightening way... and here they do a good job!
Having this strong attack and the possibility to avoid a counter, they want to attack and you should try to avoid them getting attacked first. That's not easy to make sure because they will be a priority target of your enemies cavalry and ranged units. So consider this when thinking about your tactic!
Edited by phalgast