I think this card has potential to be a sleeper, just like Stubborn Gastropod. 

I like this a lot. I wonder what happens if either you or your opponent gets a new HP before they swap back. This is the first anti-HP tech printed that I really like.

For a bad Curator deck.

Meh. It’s an Arena card.

Probably just a subpar Arena card.

I’m glad this effect is in the game, but I doubt it will be in deck lists.

Arena 

Almost assuredly terrible, but now I’m tempted to make a Wild Curator deck. Don’t know which class yet.

I expect Mech decks to want to use this. It probably won’t be bad.

A not-bad aggressive Galakrond weapon. I like it, especially in a theoretical Quest Galakrond deck.

I mean, you’re going to put it in a Galakrond deck.

Too situational for a one-off effect.

While Spell Damage hasn’t been terribly powerful in the past, it’s worth noting that typically it’s seen in Mage and most cheap mage spells aren’t burn spells. Shaman gets a lot of cheap burn, primarily because of Overload. Also, Mage tends to pay for its SD, but this seems like a bonus, even with the Overload factored in.

I don’t think Warlock will be able to take advantage of this effect nearly as well as Warrior can.

Boooo... I hate Mech Paladin.

Most of the time this will only buff a couple of minions. Not good.

If this helps summon Sparks, do they get buffed? 

Meh.  

I don’t even know what this Galakrond does yet, and this looks bonkers.

It might be time to make a Pirate swarm deck now, before RR gets rotated out.