Work in progress, as most decks are. Also, obviously ESL.

The strategy with this deck is to refuse the opponent mana and threshold by destroying their sites. To do so you need to go on the offensive early and keep unrelenting pressure while still keep playing sites yourself, thus allowing even more pressure that your opponent can't respond too. The keyword here is "unrelenting" because as soon as you relax the offensive your opponent can and will wiggle out from under your thumb and you will start to struggle as they can respond, counter and deploy threats of their own.

-- Some cards and their place in the deck --

+ Landmass/Frontier Settlers/Sow the Earth

Since Realm-Eater will be using every action to either attack or digest these cards are what you will use for expanding your manapool. I usually replace the rubble left after an attack so I can summon reinforcements directly at the Avatars location.

+ Root Spider/Hillock Basilisk/Stone-gaze Gorgons

The workhorses of the deck used to lock down enemy minions letting Realm-eater do his thing on peace. Disabling minions also makes them easy targets for the Ablaze-auras or for running them over with the Purge Juggernaut since they can't just move out of the way.

+ Everything killing off minions en masse

Since Realm-Eater needs to successfully attack a site to eat it he can be stopped from doing so by enemy minions blocking. Included in the deck are a variety of cards harmful to minions but not to Avatars. Used for clearing up blockers.

+Poisonous Dagger/Goswhit Helmet/Key to the City

Equipped on the Realm-Eater. Since he needs to successfully attack a site to eat it and only have 1 in power, a mere power 2 minion can theoretically continously stop him from doing so by following him and blocking. The dagger makes sure a minion can only stop him once. Karkemish Chimera is a primary candidate for leftover daggers.

The Goswit Helmet helps with keeping damage down while at the frontline.

The Key both gives mana and let the Realm-Eater keep up the assault no matter the terrain.

+ Land Deed

Is primarily used to bring in reinforcements behind enemy lines, ideally something that disables minions. Also used to set up the Pendulum or the Cage of Sidrak (follow by an Ablaze-aura) on the opponents side. Secondary use is to deny the opponent mana. Can be used with Scorched Earth if desperate. Beware that the opponent can cause life loss by attacking the site affected.

+ Barging Barghest

All minions can be used to play Raze but this one is especially suited for it with both Voidwalk and Movement +1 making it easy to reach troublesome sites.

+ Bedrock/Blessed village with intact Ward

Let you use Scorched Earth without actually destroying your sites. You could also play an Ablaze-aura on them to clear disabled enemy minions, even if that is suboptimal.