Like most Magic: The Gathering cards, the value of Corrupt depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (The Brothers' War)
The ability to turn an equipment into a creature is good when your opponent doesnt have the means to interact
The Ur-Dragon is one of the best dragon commanders ever printed and revolutionized this strategy, plus it uses all the colors of the Magic rainbow to access all the best dragons
However, the best choice of commander deck is whichever one suits a strategy that the player is interested in
Pinnacle Emissary looks fun for any artifact deck thats trying to win through either combat damage or sheer material
While there are Commander decks of all colors that can make use of Treasures, a handful are focused on making as many Treasures as possible, which usually require two or more colors