Investigate the Ancient Castle after moving Figaro underground, visit Cyan’s dream at Doma, and explore the Colosseum.
Walkthrough
Move Figaro Castle underground and stop when its crew reports an obstruction. Explore the passage to the Ancient Castle and examine Odin’s statue. Transforming Odin into Raiden later is permanent, so consider Odin’s speed bonus and Meteor before making the exchange.
Sleep in Doma with 
Cyan in the party to enter his dream. Work through its linked scenes and defeat 
Wrexsoul; search the throne afterward for Alexandr. In Thamasa, 
Strago and 
Relm can begin the Ebot’s Rock quest, where the talking chest asks for coral.
Search for the eight dragons, including the two inside Kefka’s Tower, to obtain Crusader. 
Doom Gaze can interrupt airship travel and yields Bahamut when defeated. With 
Locke, visit Narshe’s locked weapon shop and choose between Ragnarok magicite and sword in the original game.
Checkpoint
Cyan’s dream is a one-time sequence, so save before resting at Doma. First reunite the separated party members, then proceed through the dream train. On the train, a metal weight interacts with a moving chest, and a later switch puzzle asks you to reproduce a chest pattern. In the armor cave, reverse direction when the circular route repeats; save before Wrexsoul.