Board Thread:Questions and Answers/@comment-11700680-20170307042318/@comment-26154973-20170307051937

Maybe you can do like 10 2-3 runs per day and be done in ~2 month? Should be ok for the next event (assuming you will need subs, so far they are used in events once in a blue moon, with this last event being somewhat different). And you can do many quests there.

Otherwise, 5-3 is used to level Maruyus, but idk if it's sane to level your whole sub fleet like that, instead of leveling them passively while doing something "useful". The other "useful" thing aside from Orel is using your sub fleet(s) in 5-4 for ranking.

E.g., here is a graph for one sub, I'd assume big spikes is 5-4, while other stuff is 2-3 (level 80 is just ~300K exp.)