This is a basic xenan deck with tyrant in the 5 spot where a number of other dudes might go. Tyrant isn't optimal, it is probably better to run lifesteal in the 2 slot, but i like the card and have been wanting to take him off the bench. His effect is slow to get going (and is good early against aegis), but if it does, it's strong. Hopefully DWD gives this guy the body he deserves someday.
The 3 spot is the most contested in this deck. I've tried instigator, raider, magus, and dawnwalker. Due to the inclusion of extra 5 drops with high attack, I'm using dawnwalker currently. Raider is fun, but a little anemic. Magus works well when there is a ton of fire aggro around. Dawnwalker is the all around best unit for the spot, but tends to be best when armory/control is prevalent.
I know some people hate mystic, but he is the end game plan for this deck. He works well there.