Did you ever feel that MGSV was missing something? If not, did we play the same game? One thing that I always felt to be extremely lacking in this series is a co-op function. This mod on github enables two (or potentially more) players to play MGSV main ops or side ops together, just like it's predecessor Peace Walker.
I was doom scrolling youtube before work and saw this video and thought I'd share as an example of how the mod works.
I was looking at MGS: DELTA, but unity engine makes it unplayable on my aged pc. I've been replaying the original series in chronological order. So you could always do a re-run, I guess.