The primary reason why warlocks are the worse class in this expansion is because a huge clunk of the warlock’s cards goes into two very distinct decks:
Murlock
- Rock Bottom
- Chum Bucket
- Voidgill
- Azsharan Scavenger
- Bloodscent Vilefin
Curselock
- Sira’kess Cultist
- Dragged Below
- Za’qul
- Abyssal Wave
Control-based decks
- Gigafin
When one deck fails to make the cut, the entire line of cards fails. You can’t really use them in other decks because they are very specific in what they do and cannot be synergistic with other decks.
This is a very disappointingly poor and lazy design.
How I would buff warlock:
Rock Bottom
Summon a 1/1 Murloc. Dredge and draw a card.
Note: This is a replacement for tour guide or kobold librarian that is usable in all decks.
Bloodscent Vilefin
Battlecry: Dredge. Change it’s Cost to Health instead of Mana.
Note: 4 mana 4/4 and paying the health is a reasonable card without the Murloc restriction.
Dragged Below
Deal 4 damage. Give your opponent an Abyssal Curse.
Note: For a 4 mana spell that deals 4 damage. It is not unreasonable to enable the card to hit the opponent’s face.
Za’qul
Battlecry: Give your opponent an Abyssal Curse. For the rest of the game, your Curses heals you for 2 health whenever they deal damage.
Note: Make the effect last for the rest of the game and include other curses. However the healing is capped at 2.
Abyssal Wave to 5 mana.