Its a powerful mechanic on its own that requires very little setup to be good, but once you have these mighty pieces in play, the skys the limit
The Precon List Before we talk upgrades, let's take a look at the stock list to see what we're working with: A lot of folks say Hosts of Mordor is an unfocused pile of cards but this is just a poor shallow analysis of the deck: looking at the numbers indicate that it's pretty well-focused on Graveyard and Spellslinger: I count 27 Graveyard cards, counting any card that mills (Forbidden Alchemy), discards (The Balrog of Moria), reanimates (Extract from Darkness), or can be cast from the graveyard (Wake the Dragon)
Ral, Leyline Prodigy has a bunch of abilities too, but all we really care about is that -8 ultimate, and the fact that Ral comes in with extra loyalty counters for each instant and sorcery you cast that turn
Gev, Scaled Scorch Lizard burn shall be a deck, and Gev, Scaled Scorch is that decks emperor