All the quests are worse than the same decks without them. You don’t lose to the warlock quest, you lose to darkglare doing darkglare things and carying a subpar card. Hunter is only good because of the amount of warlock in the meta, pirate quest is fine and the deck is worse with it
Number one, the quest deals 6 damage to the opponent and heals you 6 while you‘re doing darkglare things. Number 2, the quest bonuses reduce the cost of flesh giant twice for free, bringing it out faster. Number 3, once Tamsin comes out, all your cards kill your opponent.
The version of the deck that is best now has dropped the molten giants and the Barrens Tamsin+Power Overwhelming for Crystalizers and Unlicensed Apothecaries. With darkglare, it can often complete the quest on turn 4. Even without, Tamsin comes out on turn 6 and ends the game on turn 7. It is definitely a stronger deck than the old darkglare deck, which lost to taunt walls and board clears. Hand lock could beat old darkglare, but cannot beat Demon Seed. Control Warrior could beat old Darkglare, but cannot beat Demon Seed.