the upped version is probably fine since it only costs 4
...
6
for the unupped puts it on the edge of the rainbow favoring zone. (e.g. rainbow will be favored due to higher quanta production)
Also, without either the mark-based effect or being placed in a non-
element, this card is a prime candidate for fractal spam via nova or immolate.
The rampup mechanic poses issues similar to those of the attack-swarm mechanic, though a little less potent numerically.
All you would have to do is make sure the first creature slot is occupied by something with a non-zero attack to get the ball rolling and the snowball effect can begin. I.e. Slot one would be occupied by either one of these with an attack boost or any attack capable creature.
-> this mechanic scales as N*(N+1)/2 damage vs N*N damage for attack-swarm... its a little more subdued but fractal combos could still pose a problem.
