Infection Achievement!

ive been playing halo reach since the beginning of its release. ive gotten all the halo achievements in each game except for halo wars. but the one achievement i cant get in reach is the “ALL DONE” achievement. where you have to be the last man stanging on an infection defiant map pack. but when i play infection theres no defiant. when i play squad dlc theres no infection. SO I AM ASKING WHAT PLAYLIST IS THIS ACHIEVEMENT UNDER SO I CAN GET IT?

Living Dead

Condemned shows up there, but only if all twelve players have the Defiant Map Pack which is extremely rare because of the lack of players who own the Defiant DLC.

Your best bet is to search with eleven others who own the Defiant Map Pack and full party boost for it, which is completely allowed.

Yeah I just finally got that one
Still have 1 or 2 left till 100% with Reach