Octopath Traveler 2 - Unfinished Tunnel

You must force your way into the tunnel, using either Ochette or Hikari in the day, or Throne or Castti at night. Upon entering, you will get the sidequest to beat the boss of this place, which is very similar to the Malboro from Final Fantasy. To my knowledge, there is no "ribbon" accessory, but you can equip certain ones to block specific status ailments. It would have been nice if a NPC or something warned you about the strategy in advance so you didn't have to go in blind...

If you want to have an easier time here than I did, get everything the passive status immunity from the apothecary job. This will protect you from the opening barrage. Once you get past that, you can have Castti whip up something to periodically give status protection. I don't think I had that many of the ingredients at the time of this recording, so I was very hesitant to try using it, but it can save you a headache. There are places to buy the ingredients you need, but I went in here blind without knowing what to expect, so I did not get to stock up as I would have liked.

The other option would be to have the divine skill that causes single target skills to go AOE (or bring Agnea with apothecary subjob) so you can use the apothecary immunize skill on the entire party. You may want to equip that character with something for SP regen as you could risk running out if you're not in position to overwhelm it in the short term (which I kind of am...)

As for the boss, if you can mitigate its status effects, it doesn't have anything else going for it. I am not entirely sure, but I think it actually has less HP than other bosses for this level range since you're given no warning of what to expect. Had I known, there were a few things I could have done differently to completely neutralize the sucker, but as I said, I am doing all of this blind rather than following a walkthrough or reloading part way through a fight (as tempting as that is)