I am also using an FFQ deck. Rustlers are essential to it, in my opinion. The speed at which a Rustler can generate Life Quanta once your Fireflies get going is incredible.
I start with a Life aspect, to start generating Life Quanta from the first turn. I can usually get my Firefly Queen out on my second or third turn. This goes well with my natural Life Quanta generation. By the time my FFQ is ready to use her skill, I have at least 3 Life Quanta. Two for my first Firefly, and one for my first Rustler.
The important thing a Rustler does, is it takes the place of Life Pillars. This opens up a few more options by giving you more room to toy with while keeping your deck down at 30 cards. The FFQ deck really needs to be kept as small as possible with very little bloat, because by nature, it is already a very slow deck.
I'm still playing around, testing, and adjusting my deck, because it is having a hard time dealing with certain decks that shut down the FFQ or Rustler. But the basic structure of my deck is this:
13 Wind Pillars (I may convert these to Wind Towers to get that extra burst of Wind Quanta early game. Late game, when you have 2 or 3 FFQ already out, Wind Quanta is pretty worthless. Ideally you want to generate enough Wind Quanta to get out the FFQ by your second turn. As by your third you are likely to have a Rustler and 3 Life Quanta to start your chain. Also, right now, every single one of my Wind Pillars are necessary if I want to have enough Wind Quanta to get out my first FFQ. Ideally, if I have all Wind Towers, I won't need this many Pillars. This will open up room for cards like the Emerald Dragon, Deflagration, Heal, etc.)
4 Rustlers (This is a good number to always have a Rustler in the first few turns. Also, it helps to keep spare Rustlers around, as they are easily taken out by everything from Lightning to Poison. By the same logic, you need to Photosynthesize every single Light Quanta every turn, because you never know when your Rustler will be destroyed. Without Life Quanta, a FFQ deck is a sitting duck. It may be a good idea to keep some Emerald Pillars for that reason. At the moment, I'm still debating if I should, since adding Emerald Pillars would mean taking out a Rustler or other essential card that would ultimately slow down my deck.)
3 Novas (Novas are very useful for dealing with Devourers and times when you need that one extra Air Quantum for your FFQ. Also, if you have a Ruster out, it can give you 3 Life Quanta instantly, which can be enough to get out an Empathic Bond or just more Fireflies. I'm testing out adding cards like Deflagration and such to utilize all the other Quanta it generates, but I need more tweaking with them and may need to add more Novas. The big problem I am having is from decks that can shut down the Rustler.)
3 Empathic Bonds (This is enough to get 2 Empathic bonds in a medium length duel usually. I find that to be a pretty good number. Too many will slow down the deck. But this is personal preference I think. More is ok, but I find that in the first 5-6 turns, the Empathic bond is not worth playing, because you don't have the Life Quanta or the number of creatures to warrant it. Thus having too many will result in dead/useless cards early in a duel if you draw them.)
6 Firefly Queens (These are my only creatures. Of course an FFQ deck must field their FFQs as fast as possible. Maximum number of Firefly Queens at six. Minimum number of cards in my deck at 30. I almost always get a FFQ by my second or third turn. If I don't, it's bad luck, and unfortunately, almost guarantees a loss. I've been thinking about using Elite FFQ's, but they would completely change the synergy in the deck. I would have to try it out a couple games to see how things work.)
1 Owl's Eye (It's the best Rare card for the deck. What can I say. It's great for taking down Otughys that can get annoying and other low health and annoying creatures. I'm thinking about adding some Lightning to my deck to increase the effectiveness of the Owl's Eye by making 4 health creatures killable in one shot and 7 health creatures killable in 2 shots.)
This makes my deck 30 cards in total. Hopefully, you can tweak your deck with some of my ideas. I love playing with and playing against FFQ decks. They are so epic when you get over 10 creatures a side and duke it out. Good luck.
