Back when Halo 2 was still the latest release, I accidentally came upon the campaign glitch that allowed players to have unlimited sword energy for levels that were played back to back with the same character. To me, this was by far the coolest glitch in the game and still is to this day. So I was happily surprised a few days ago when I found out the glitch works in MCC for levels played in a playlist that aren’t back to back in the storyline. I played the Flooded playlist and ended up with a drained sword in a Chief level (can’t recall which level ugh), only to have unlimited energy for it in the level right after it in the playlist order.
I don’t know if this was intentional or whether the game’s code works this way for levels that aren’t back to back, but it’s pretty sweet either way 