I really like this card and hope some version get implemented to the game; air could use a few more tricks in its arsenal and its an interesting concept. Its essentially a paper tiger with momentum (ignores all shields but 2, those reflect). Kinda like winds version of a sapphire charger with a twist of spell damage.
When I look at this thing, I see it as essentially a 6/1 creature (if you have 6 out, which will probably only happen with fractal) with momentun upped for 4 quanta and a 1/1 creature with momentum unupped for 2. Since this is closest to a charger in function, I'll compare it to a charger for balances sake.
Upped:
Elite charger: 7/5, 5 cost, momentum, damage per quanta: 1.4, damage with ~30 quanta and fractal: 42
Wreched swarm: 6/1, 4 cost, spell damage, damage per quanta: 1.5, damage with ~30 quanta and fractal: 42
Using fractal, the damage difference between the wreched swarm and elite charger seems quite minimal. There is only 0.1 difference in damage per quanta in the swarm's favor. Obviously 8 chargers out damege 8 swarm, so for comparison, I assume there is 30 quanta or the needed type when casting fractal. Here one could place 6 charger or 7 swarm in one turn. Both situations result in 42 damage that ignores shields. So for balance purposes, the wreched swarms damage potential comes in about the same as the fractal charger.
Now looking at defence, there is a quite huge disparity. The charger can survive any current damage spell except thunderbolt with its 5 hp and is immune to the ill effects of all the shields. The wretched swarm, however dies to every damage spell in game. RoF, thunderstorm and unstable gas can wipe them all out in one shot. Simply the charger has high survivability and the swarm does not.
The swarm also has three more things going negatively for it. First, while it generally ignores shields, jade and mirror shield act like antimatter to this card and cause it to heal the opponent. Secondly, all the data I used assumes there are 6 or more in play. In a non fractal deck, this card will likely do 1-3 damage in most games as rarely will all six be in play at the same time. Thirdly, since it is a 0/1 creature naturally and the damage is an effect, lobotomizer will not be kind to this card
In summary, compared to other cards in this game, I feel that this card is actually underpowered. I realize the N attack was the point of the card, but in normal decks it will be too weak and in fractal decks will become too strong(hence the cap). 6 seems like a good attack for this card; I suggest the attack becomes a permanent 6 attack if the cost remains 4 so this card is useful outside a fractal deck. Even at 6 spell damage for 4 cost with 1 hp I feel it is still underpowered and a weaker alternative to the charger due to its 1 hp. Due to its weaknesses and frailty, 7 damage and 4 cost may even be balanced, but probably not.
Unupped:
There is not an easy comparison for the unupped swarm, but again, 1/1 for 2 cost with spell damage seems a bit weak, and will probably never be used. Let me compare to other 2 cost creatures: The mind flayer is 2/2 with lobotomize for 2, fire spirit is 0/2 with growth for 2, horned frog is 3/3 for 2, antlion is 2/3 with burrow for 1, graviton fire eater is 0/5 with ablaze for 1, lycanthrope is 1/1 with lycanthropy for 2, devourer is 0/2 with absorb and burrow for 1, and scarab is 2/N with devour for 1. the onerous swarm is weaker than each of these.
I propose it that 2/1 for 2 quanta wil spell damage would fall more in line with what current 2 cost cards can do. 3/1 may also be balanced since its damage again can be lobotomized off.
