Hard to predict whether this would be overpowered or work well due to its high cost. Fractal Minor Phoenix would be where it would be most useful. It would be very interesting in a Fractal Brimstone deck, too, since it would be easy to get the quanta. Well, I suppose with Cremation, it would be pretty easy in a Minor Phoenix deck too. I think those two cheap creatures would break this card, as +3 is a pretty substantial bump. Brimstones would be as effective (or more) than Pests at boosting your quanta, so playing a 10 cost card with them would be no problem. Plus they already start out with 2 attack. With Eclipse, you are talking about creating a field of 2 damage creatures using cheap creatures (Pest) you can spam. Fire's cheap creatures (Minor Phoenix and Brimstone) already start with 4 and 2 attack. +3 to those I think would be overpowered, regardless of cost. Brimstone might be reasonable (Giant Frog only costs 2 and it has 5 attack), but I think the existence of Minor Phoenix makes this effect too strong.