Arcanyst faie's hard to beat without aoe, Abyssian can flip the course of the game with death knell, and songhai can deal massive amounts of damage at once.
To beat faie you need:
-Sufficient damage to end it before it gets out of hand.
-Aoe to get rid of illusionists
-The will to take a beating. Her arcanysts often don't do a lot of one turn damage, but their overtime threat is what you should look out for.
To be Abyssian:
-Health in the late game
-A way to end the game before late game
To beat Songhai:
-Sufficient control. They often deal with threats by killing or turning them into a panda. High stat'd or forcefield minions are pretty good against them.
Control also helps endsure that ranged units dont get too far away.