Sawblade rush is simple. Once you have Thadius [Mission 10 reward] and have 100 rank points in the arena [Easy task], you can build a Sawblade Rush deck. Just buy 7-10 Sawblades and use Thadius. If you run only 7 [Or even less], your others can be a number of possibilities. Some good choices being Cerberus, Orbital Cannon, and Harbor Command.
Sawblade Rush will get you through missions 11-28 easily. Once you are passed mission 28, you will most likely need to change your strategy. Also, there may be some missions that Sawblade rush doesn't work for, so have a secondary deck ready for this.
A good example of a Sawblade Rush deck.
Vampire rush is a lot like Sawblade Rush except that it's not as easy to get the cards, [You can only pull Vampires and Asylums from Silver/Gold packs] and you need 2-3 Asylums + Malort for it to work.
It may not sound so worth it but Vampire Rush will get you a lot farther than Sawblade Rush. Not only that, but you get a Hatchet from mission 28, which makes the deck even better. Also, Vampire Rush does not have to entirely rely on Vampires. Other cards that work well in it are Annelid Mass [Early on], Blood Grunt, Locust Swarm, and Moloch. Annelids and Blood Grunts can be pulled from Silver/Gold packs. Locust Swarm can be pulled from Silver/Gold Packs and if you play Tyrant on Facebook, can be gotten through Gifts. Moloch can be bought in the Reputation rewards.
A good example of a Vampire Rush deck.
Impulse Rush is arguably the best of the three in the end considering it is built and used correctly. Early on it is good, but once you get your hands on a Command Center and get Fury Walkers from the Nexus missions, it starts to crush people, even in late game. This build, however, requires you to use 2-3 Rally Flags.
You first need to start with 2-3 Rally Flags, then consider how many Grunts you have [1/4 Raiders]. However many slots you have left after you have placed 2-3 Rally Flags and 0-3 Grunts, is how many Impulse Walkers you buy to fill the rest of the deck. That is, at least, the initial build. Like stated above, you win Fury Walkers in the first several Nexus missions [42+] and once you acquire a Command Center, Impulse Rush can really destroy, even in late game.
This is where the games difficulty really starts to have substance and should be about the time you start buying gold packs. The variety and kind of decks used from here on out become larger, however, I will list what I think are the best paths to take.
-1. Standard Multi
-2. Aggro BT
-3. Aggro Raider
This is the path which I recommend taking more than any other because I know from experience and have helped other friends to know that SM decks are the best and easiest to build. This is mostly due to two things.
1. Half of the cards which are great for SM decks come from Quest Rewards. This includes Hatchet, Arc Trooper, Cannon Walker, Rifter, Exodrone, and Predator.
2. Since you aren't tied down to just one faction, your chances of pulling a useful card out of your gold packs are much higher.
There is no set cards to use. The basic idea is to just take the best non-faction-specific cards you have and mix them into one deck [Ofc, start with using the above listed cards once you get them].
The commander depends on what you have available. Primary choice commanders would be Atlas and Dracorex. Secondary would be Duncan and Sidoze.
Take whatever "Elite" cards [What you consider the best cards you have] you have and use "Fillers" as temporary's to fill the rest of the deck. What I mean is, at this point, you most likely wont have enough or the right "Elites" to build an entire deck of them so here is a list of good "Fillers" to use until then.
Aggro BT is simply a more advanced and quality version of the Vampire Rush deck which doesn't rely on Vampires so much. Cards like Malgoth, Draconian Queen, Blood Spout, and Brood Walker may be available to you now.
A good example of an Aggro BT deck at this point of the game is.
Just like Aggro BT, Aggro Raider is simply a more advanced and quality version of the Impulse Rush deck which doesn't rely on Impulse Walkers so much. Cards like Command Center, Havoc, Cannon Walker, and Omega may be available to you now.
A good example of an Aggro Raider deck at this point of the game is.
x2 Rally Flag
2x Fury Walker
x2 Impulse Walker
By the time you are finished with the first set of side missions, you have a choice. To jump into faction play or to continue on with the quests. I will be one to say that the rewards from missions 42-66 are not impressive outside of Poseidon, Mawcor, and Fury Walker. The rewards that ARE impressive are the ones from the second set of side missions, however, none are "must-haves". So starting faction play at this point isn't really a bad idea.
These are the two kinds of decks you should be running at this point.
-1. Standard Multi
-2. Xeno Muscle
There are ofc. other tier 2 deck choices such as Aggro Raider and Aggro BT, however, they don't get the job done quite as well as the two above.
This deck has already been described above, however, at this point, you have opened up a lot of better options from packs and quest rewards. Your deck should now look something like this.
Other variant choices being Hatchet, more Daemons/Hatchlings, EMP/s, Airstrike, Apex, Omega, Ragnorak, Chronos, Sabre/s, Phoenix, Poseidon, and Draconian Queen. Anything else is Tier 2.
By this time, you may have accumulated a bunch of really nice Xeno cards and a Vyander. This deck is designed to overpower and decimate your opponent, however, it is slow for the most part. Your deck should now look something like this.
Other variant choices being, Enclave Warlord, Mind Controller, Xeno Interceptor, more Daemons/Hatchlings/EMPs, Dragoon Hunters, Ragnorak, World Quaker, Airstrike, Vaporwing, Enclave Pylon. Anything else is Tier 2. Please also note that it is possible to build a successful Xeno Muscle deck with Dracorex and Atlas as your commander.