Sine Mono-Green decks generally are creature and combat-focused, this makes Craterhoof Behemoth especially terrifying, as the X values will likely be very high, allowing you to swing out with giant creatures, all that gain trample to likely take anyone, if not the entire group of players out in one combat phase
Do this for each card
Not only did it open us up to four-color identities that we didnt have access to before, it created some of the most popular generals in the format
Aurelia's Vindicator can potentially switch into Mulldrifter - or even Titan - mode when you have enough mana
As it turned out, USPCC contributed only a small percentage of the total population of the Fourth Edition set
While you'd be hard pressed getting the mana together to pull them off, Brinelin's partner ability means you could easily pair it with a green Commander and make use of that color's many mana ramping abilities