Semi-bump.
In the propose, an unuped Mercenary cost 3, and a pillar cost nothing, so total a 3 cost and 2 cards to put a 3/5 creature in the field and one PC.
An unuped Explosion cost 3 as well, and you still need to pay a 3/5 creature (which at least cost 3 while unuped) to make 2 cards same as Guard + pillar.
It is a 3 cost different.
An uped Raider cost 3, a tower cost -1 (gives you 1).
While an uped Explosion cost 2, and you still need to pay a 3/5 creature (Let say you use one 2 cost uped to do the same job) to make the two cards close to yours.
It is a 2 cost different.
(Well even the uped one cost 3, it still only cost 2 cost and 2 cards to being a creature and doing a PC.)
Even it prone to CC, they are still way too good.
Sorry for taking a while to respond to this, but I feel it's necessary to fully explain why I feel Smash is balanced:
While cost compensates for Mercenary, it still has to deal with limited options in the unupped front - not to mention it is also one turn slower, but Smash is only more advantageous for 2 | 1 turns as shown below:
Explosion wipes the pillars off the field permanently - that's 3 | 2
up front.
Graviton Guard / Merc costs 3
for 3 attack, so let's assume Smash is a 0 0 | 1 creature with
Smash -and- the ability
'Swift' (this creature can its ability when played).
Smash always costs 1
for an immediate delay, so the cost difference is 2 | 1
if you win the game the turn you use Smash..
If you take another turn to win the game, you must pay a 2nd 1
. You now have spent 2
on Smash, so cost superiority is now 1 | 0.
If you take 2 more turns to win the game, you must pay a 3rd 1
. You now have spent 3
on Smash, so cost superiority is now 0 | -1 (you're become less efficient).
Overall : Unless you win the game within two | one turns of playing Guard/Mercenary, Explosion will end up better in the long run after the first 2 | 1 turns.
This does not begin to consider:
- You need to wait one turn to trigger Smash. vs. you can trigger Explosion at any time.
- Mercenary can never target pillars. Guard can never target certain cards like Hourglass, Graveyard, etc... vs. Explosion destroys any Permanent.
- CC kills a Guard and reactivates a permanent. vs. Explosion permanently deals with the card.
Even with the most basic denial example - 1 pillar vs. Explosion and 1 pillar vs. Guard, you'd lockdown with Explosion quicker since you need to only gather 3
in one turn (and fire has Immolation) while Guard has to gather 3
, wait one turn, and then Smash the pillar for 1
.