Druid: Naturalize (1 mana), destroy a minion and give 2 cards to the opponent.
Warrior: Execute (1 mana), destoy a damaged minion.
Priest: SWP/D (2/3 mana), destroy a minion with 3-/5+ damage.
Rogue: Assassinate (5 mana), destroy a minion
Hunter: Deadly Shot (3 mana), destroy random minion
Warlock: Siphon Soul (6 mana), destroy a minion and recover 3hp to the warlock
Mage: Vaporize (3 mana), destroy a minion who attack the mage.
The only one of these cards gives a bonus to the opponent: Naturalize. You might to think something like "but it costs 1 mana only, all is OK!", but if you compare it to other cards - this argument wont be looks well.
- You can hit a minion for 1 damage and use Execute on it. Does 1 damage costs 2 cards? Don't think so.
- Priests: only a few mobs in game have a 4 attack and gives a real pain to the player: Izera, Drakes. But they are so dangerous not because of their hp but becouse of their effect for player. Priest have 4 cards of silence for such cases. More than enough. And 4 "just destroy" cards for minions that are "not 4 attack".
Rogue: just kills any mob for 5 mana.
Hunter: 3 mana for killing a random minion. Ask youself: how often you do see an opponents that use "i swarm the board" tactic? I had seen it very few times, most players use a "clear opponent's side of board and have one minion on my side". In other words this "random shot" does not looks so "random".
Warlock: 6 mana. It is for 1 more mana than simple destroy (rogue) and it is recovers 3 hp to you.
Mage: Almost the same thoughts that were about a Hunter. The price is the same also.
And the other question is: who needs a "destroy" button on early game? Why 1 mana? Nobody will use this card at it's first turn. Make it costs 5 mana, but remove this "gives 2 cards to the opponent" from the card - it will be absolutely OK!
Because now Naturalize card are absolutely a tresh card and nobody uses it. Giving cards to the opponent is absolutely bad idea!
I used this card effectively only once: opponent was without cards in deck and started to get damage from fatigue. I killed two of his minions and he took a lot of damage. But I do not think that using this card in that way is a planned design.
I don't want to take into consideration the cards that are related to some sort of control like "sheep", or "hex", or should be used together with other cards like equiality.