Maybe call it the Explosive Promo?
I dunno. I'm going out on a leg here and saying that people liked the slime promo, and I've always wanted a blast cube themed costume.
It could be like this:

Blast Cube Costumes: Yellow-Orange costumes made in the style of node slime costumes, but with similar texture to the blast cubes found in tier 1
Super Blast Cube Costumes: Red-Crimson costumes textured just like the blast cubes found in tier 2
Ultra Blast Cube Costumes: Purple-ish costumes that look like the blast cubes found in tier 3

Blast Cube Bombs: These bombs act like the shard bombs, in that they separate into little chunks just like a tier two-three blast cube, which then proceed to explode again, dealing higher damage than the initial separation blast. Maybe the actual bombs are shaped like a cube, and textured like the blast cubes? Heck, we should make three of them. It works like this:

Tier 1 Blast Cube Bombs: Yellow-Orange cubes that explode only once, dealing higher damaged than the others
Tier 2 Blast Cube Bombs: Reddish cubes that explode once, then separate into little chunks that explode again
Tier 3 Blast Cube Bombs: Purple-ish cubes that explode once, then separate into even more chunks that explode again

They could have crafting recipes just like tortofists, maybe being an upgrade to the Shard Bomb?

I dunno. I've shared my idea. Thanks for reading! Comments appreciated!