It's Hip to Be Squared.

Super ally swarm for Nebula. Why? She has rather low health, so lots of blockers are good. The usual problem with this is that it leaves her economy drained so she can't really make use of her upgrades. Rather than going for burst with Blaze of Glory, we're going for complete sustain with mass allies. We're also going heavy on the economy so that we can do Nebula things and allies. We're going to be wanting to flip relatively often so we can keep triggering her AE card draws. Usually this will involve Professor X, Evasive Maneuvering, or have Cutthroat Ambition in play (to deal with the extra threat). We'll also want to be focusing on getting the economy supports in play.

So reasons for various choices: Beast is essentially a 2 - 3 cost effective ally with a double or Band Together with 3 allies. Black Panther allows you to get "Welcome Aboard" or Squared Off (usually Welcome Aboard) for extra economy for your allies. Nick Fury is also cheap when you take the Draw 3. Call for Backup is ideal to have out if you need to turn thwart to economy (via Beast, Black Panther, or Nick Fury). Especially, useful to leave around in case you want to play Cutthroat Ambition for cards in AE, but not much threat to remove (because the villain is confused) or you have excess thwart removal via 2 Cutthroats. I have been finding Domino to be a fantastic ally for Nebula. Sometimes you'll draw a Lethal Intent on a turn you're planning on flipping down... so you start the turn with no upgrades and you want to flip to AE and get cards from your upgrades, so you don't get to use Lethal Intent. With Domino, you put Lethal Intent on top of your deck and sometimes get extra economy or an ally when you have economy.

I find with this deck or any Nebula deck that is going to be focus on the upgrades is to track what's been used and what's coming up. This is important for decision making with Combat Ready. Sometimes if you're near the end of your deck or you have no upgrades left, it's best to shuffle in two of the best upgrades for your situation in so you draw them and can get cards from them while in AE. If you have something like Evasive Maneuvering or Unyielding Persistence left in the deck, I usually like to mill for them because they're so strong.

This is more of a death by 1000 cuts kind of deck than a burst damage deck. Though, the late game can allow you to Lethal Intent on two Weapons Master you have in play when it works out. It does a fair bit of damage for cheap.