Get the Crimson DLC achievements? I have a few of em, but some of them like getting a kill while a warthog is flying is a little difficult…I know that in wreckage you could use the lift behind the red team’s flag…but most people wouldn’t do that if I’m gunning.
And I suppose you just have to play shatter enough to get the mantis stomping…
Lemme know if any other ideas…
P.S.
Outside of the DLC playlist, I have never gotten a DLC match 
classic.