The final reward for this should be "All fatigue damage effects your opponent instead" That way the Questline decks would be more Control focused decks. There wouldn't be as much reward for going full aggro Questline.
It would still beat all other control decks, but aggro would punish it. Right now it is an aggro deck, that also beats all other control decks.
No , if anything the Quest needs to be changed so that fatigue damage doesn't count. Every Warlock deck i'm running into in wild, basically has drawn their entire deck by about turn 8 and kills you with fatigue with multiple copies of Hand of Gul'dan.
So basically if you're not playing aggro , you can't win. Which would be fine if the deck wasn't all that popular. But it is, and its fucking everywhere.
I think it's a good question weather the quest line should be used for countering slow defensive decks or work as a tempo card for flesh giant with potential late game burst. I thought of even changing the last step to require fatigue damage in order to get to Tamsin, so that the card would be full on delete lock. Remember that warlock already have Jarraxus and Tickatus to counter slow decks, so it's more a question of how flexible the quest line should be IMO.
I dont like Blizz. Primarly cause their insane strongly profit related corp. management. But I'm kinda impressed how they handle to balance HS every patch. Yeah there is always a stronger deck and stuff. But the balancing is impressing, if you look at the variety of opportunities.
I dont think what you propose is the correct solution to the warlock quest line as it's mostly the fatigue damage that kills people. For me any quests that essentially have "win the game" as a reward should be as slow as the priest one if they exist at all (and I'm not convinced anything like the current quests should exist in Hearthstone given the lack of interactivity with the opponent, but here we are).
These quests all share the same problems that The Caverns Below created and the biggest issue is that they broadly don't care what the opponent does - the most important thing is completing the quest, because they pay-off is so large. That's a poor design in my opinion, as the only way to beat them is to kill them before they complete it. That means it's either a quest race or an aggro race.
1) Get 6 dmg and then do lifesteal for 3. Net is that both are at 27 and you got something nasty done with the damage to self
2) Get 7 Dmg and then do lifesteal for 3. Net is that you are 23 and opponent is 24. Ooo scary kinda like free dmg
3) Final reward is 8 dmg which doesnt heal you back ending up 15 to 24 but if you failed to get any advantage in the first 2 steps while knowing that you must get dmg you have played wrong. Not to mention all the cards you can take dmg without actually taking dmg.
Most absurd is that for a fast deck you can still outplay long game. Breaks all RPS :)