It's also quite effective to use Parasite Swarm. It can take over Skyfire Drakes and Scythe Fiends, deal great damage against Enforcers/Gladiatrix and can even snipe Firedancers over cliffs. Just be careful, because they have a very low healthpool and one shot from a Drake + Eruption and they're dead.
You can send Energy Parasites to distant places, forcing the Fire player to summon a Skyfire Drake. Even if this kills your EP without leeching a well, it will force 100 power for the Drake far away from the action.
Ghostsspears + Spirit Hunters are a quite strong early game combo.
Don't use Burrowers, if you want to attack just use Deep One instead.
Whatever you do, don't rush/stay in T1. Pure Fire T2 is extremely strong against Nature T1.