The best colors for Dragon Commander decks are green, which is the most important color due to ramp, while red provides Dragons, haste, and damage
ZA: Esper Charm
Command your army with the Mythic Spirit Dragon, Teval, or Kotis, leader of the Sultai clan
While I cant be certain of the latter, I can say casting Catastrophe for land, or any other Land Destruction spell, comes with huge cost and risk for the player playing it, too
The original piece certainly has its place, setting a precedent that Urza built a lot of machines that looked the same, one of which was lucky enough to become Karn
Andril, Flame of the West Andril, Flame of the West gives a huge +3/+1 bonus and gets you some 1/1 Spirit tokens