Starting Obaro’s sidequest is a bit odd, as you will need your actual ship and will have to sail over a specific spot on the map. Your destination is the western side of the southcentral island, which is the one with Ragness Ruins on it. Finding a way there is a bit tricky, simply because a lot of the sea is lost, but when you finally manage to get there, you will bear witness to a scene on your boat. Thankfully, Obaro wants to go to Ragness Ruins, with the dock being right there, so drop anchor and enter it for more scenes. When you regain control, you will need to head back to Ragness Ruins. Before you do, though, make sure you save your game and possibly eat a dish that buffs your characters, as you will get into a boss fight after some dialog.
BOSS - Odeon
Odeon is pretty much a mirror of Obaro, down to his attacks, so if you’ve been using Obaro a lot in your party, then you kind of know what to expect from Odeon. You will want to be careful about placing your characters too close together, since Odeon’s spells tend to have a smallish area of effect to them, so they can hit more than one character at a time. Dianto’s Steadfast is a very good skill to have in this battle, since it will raise everyone’s magical defense (and physical, but physical defense is useless). Couple that with Magical Mar and instead of the 300+ damage Odeon will normally be doing, it will be doing less and make some of your characters more survivable. Outside of Venom Mist, which can poison whoever it hits, there isn’t really a strategy for this battle outside of just healing.
After the battle is over, you will receive the Chrono Spritnite, which you can use to get the Meteor skill spritnite at any magic consortium (you also can use memories to get extras).