We still need another couple of red commons, a player burn spell, a general burn spell, and something else.

This is taking the place of a player burn spell. It's deliberately a sorcery because I wanted it to fulfil the roll of "force through last few points of damage" rather than "aha! gotcha!", although you could do the other.

It was originally going to give the creature some form of evasion, but I thought trample was plenty. In fact, I'm surprised red doesn't have more like this: it seems to fill exactly the same slot as fling or goblin grenade, but be more creature combat-y.

But this is a throw-away idea, so feel free to suggest something else or something on-theme.

Nice take on Lava Axe. Very good on a random 4/4, but much more vulnerable to being tapped, fogged, etc. I like it.

I like it too. Probably doesn't need to cost , since it still requires a creature to be in play and attack. I know the trample can give you more value, but the requirements seem to outweigh that.

Removed the "(Sacrifice it at end of turn??)" not because it isn't a valid question, but that these cards are getting close to testing, and I don't want to confuse the playtesters.