What about this: let's make it 6
3|2 / 6
3|4 and give it
Amass: at the beginning of each turn this card is in play and not frozen/delayed, one new Avalanche enters field
Momentum
Amass wouldn't be stackable - i.e. no more than one Avalanche/turn enters field automatically. It would give you +3 Att per turn, but could be easily countered by Ottys, or Fire Bolt/Rain of Fire(unless upped). Anyways, the quanta cost is somewhat weird...
Man, I don't know how to defend my ideas... ;P