Losing a one-sided fight, Equestria has been invaded by their long time enemies, in hopes of breaking open the oyster to harvest the pearl within. The Elements are useless against an army. The Royal Guard are inferior in both numbers and equipment.
As a desperate last move, the princesses ask for help from a general who definitely has the power to turn the tide of this war. Thinking that this was all just a prank, he sends "help" in the form of wrecked enemy vehicles and a single construction dozer that got mixed in.
Crossover with C&C Generals ZH