Hunt 15: The Mine Flayer
Mindflayer - Rank IV

You can obtain this Hunt after you have defeated Judge Bergan after completing the events at the Stilshrine of Miriam and returning back to Mt Bur-Omisace for the second time.

Petitioner
Warrior Guromu can be found in the Lull of the Land area of Jahara on the south side of the zone.

Speaking to the Warrior Guromu to initiate Hunt 15: The Mine Flayer for Mindflayer
Map of where to find Warrior Guromu in Jahara

Location
The Mindflayer is located in the Phase 1 Dig area of Henne Mines. Warp to the Henne Mines by way of an orange Save Crystal, travel north and go through the doorway that leads back to the North Entrance. Travel south into the Phase 1 Shaft and then south again into Phase 1 Dig. Mind Flayer can be found towards the southern section of the zone.

Going through the North Entrance of the Henne Mines
Traveling through the Phase 1 Dig area of Henne Mines

Hunt Battle: Mindflayer

Level: 35
HP: 31,161
Steal: Pebble, Float Mote, Vanishga Mote

Mindflayer is one of the more difficult Hunts from a strategy point of view. It has a move in its arsenal called Time Requiem which will inflict the Stop status effect on all of your party members. There is a good chance that, even if all of your party members are hit with the Stop status effect, that you will survive and potentially recover. But you risk having to constantly dig yourself out of a hole and will have to over heal in between just to stay alive.

Once inflicted with Stop, Mindflayer will also cast Blizzara and then hit physically as well. Make sure that you keep Shell on all of your party members for the duration of the battle. Use any items, armor or accessories that you have that raise Magick Power as this will help your party members resist the status affect. There are no items available currently that can prevent Stop if you are attempting this fight as early as possible, but if you are attempting it later in the game, you can pick up a Power Armlet accessory and equip it on your party members.

Mindflayer casting Fira during Hunt 15
Battle against Mindflayer

You can also use the Nihopalaoa and Remedy trick to inflict Berserk and Slow on Mindflayer to make the battle much easier.

Return to Warrior Guromu in Jahara to receive your reward which includes 2,200 gil and a Carmagnole.