Instructions
Kill Hydro. He is the first boss in Pharos at Ridorana and appears almost as soon as you enter the area. He is vulnerable to light damage and isn't difficult to defeat. Hydro uses negative status effect attacks, but Esuna and Remedy can effectively cure them.
Cast Float on all of your characters. Keep your characters floating until you reach the Empyrean Ravel to avoid damage from traps and earth spells.
Examine the Carven Pillars to start the next puzzle.
Kill enemies until you get three black orbs. All of the enemies in this area drop them.
Place one black orb in each of the three Alters of Night. The Threshold of Night -- the door blocking your path to the Dunes of Profaning Winds -- will open once you have done so.
Follow the rightmost path through the Dunes of Profaning Winds. Taking the wrong path teleports you back to the beginning of this area. You will encounter Pandaemonium, the next boss in Pharos at Ridorana.
Defeat Pandaemonium. He is weak to wind damage, has high defense and can inflict the blind and petrify status effects, but he is not particularly challenging.
Examine the Waystone at the beginning of the area to open the doors blocking your path to the next part of the area.
Defeat the green Brainpans to create bridges, which will allow you to go further into the area. Killing the red Deidar destroys these bridges, so avoid them completely. You can rebuild bridges you accidentally destroy by killing more Brainpans. Eventually, you will reach Horizon's Break. Follow the path to reach Slyt.
Defeat Slyt. He can inflict a lot of damage, so watch your health. He is weak to fire damage. Cast Oil on him, followed by a fire damage spell, to inflict large amounts of damage on him. With this combo, you should be able to defeat him quickly.
Touch one of the four different colored alters in the next room. You only need to touch one of them to open the door. To proceed further, you must give up the ability to use attacks, magic, items or the mini-map until you've finished the next boss fight. Giving up items or the mini-map are the best options. Head deeper into the area to reach Fenrir, the next boss.
Defeat Fenrir. Have the highest defense party member cast Decoy to get Fenrir to attack him. The only danger in this boss fight is the sheer amount of physical damage Fenrir can inflict; you can mitigate this danger by keeping him attacking the party member with the most defense and keeping that character healed.
Touch the alter in the next room corresponding to the one you touched before. Doing so will restore whatever ability you gave up previously.
Touch the black, green, red, sacrificial color and clear Sigils in that order to proceed. The sacrificial color Sigil is the Sigil matching the color of the alter you touched earlier.
Proceed through the area until you reach Hashmal. He essentially marks the end of the Pharos at Ridorana. The rest of the area primarily consists of the remaining boss fights.
Defeat Hashmal. Keep your party floating throughout the battle; Hashmal uses earth magic, and if your party is floating, its members will be immune to much of the damage he can inflict. The only threat he poses is his ability to cause the disease status effect, which you can easily cure. He is most vulnerable to wind damage.
Defeat Judge Gabranth. He doesn't have any special attacks or vulnerabilities; he just inflicts basic damage. He becomes immune to all spells halfway through the fight, but otherwise he is an unremarkable and easy boss.
Defeat Dr. Cid. Halfway through the fight, he will summon Famrit. Cid cannot be harmed while Famrit is summoned. Famrit is weak to fire damage, so the oil and fire spell combo from before is an effective way to kill him. Once you have defeated him, focus on fighting Dr. Cid again. When you defeat him, the cutscene marking the end of Pharos at Ridorana will begin.