Final Fantasy 15 Dungeon Guide – Costlemark Tower

Final Fantasy 15 Dungeon Guide - Castlemark Tower
Final Fantasy XV is filled with awesome dungeons that will push Noctis and friends to their very limits. This Final Fantasy 15 Dungeon Guide – Costlemark Tower focuses on the Costlemark Tower that features level 50+ enemies and the chance at nabbing yourself and awesome Royal Arms weapon. Completing Costlemark Tower is one of the requirements to obtain the special key that opens the special locked doors in all dungeons.

Where Is The Costlemark Tower Dungeon

Where Is The Castlemark Tower Dungeon

How To Get Inside Costlemark Tower Dungeon

The Costlemark Tower dungeon appears impenetrable from the exterior during most times of the day. As the dungeon is inhabited by exclusively by demons, the entrance only becomes visible at night. Simply return at night and you’ll see the stairs have extended and the route through the entrance is now open. Make sure to walk over the strange object on the floor to trigger something later.

Costlemark Tower Dungeon Guide – Requirements

Costlemark Tower is one of the toughest dungeons in the game so make sure you come prepared for a fight.

  • Minimum level 50+ (higher the better)
  • 4-5x Magic Flasks filled with all elements. Bring extra Fire if you have a choice, save a Blizzard for the boss.
  • Tons of healing items
  • Ability to cure or be immune to petrify (boss battle)

Costlemark Tower Dungeon Guide – Monsters

Costlemark Tower is home to a variety of incredibly powerful enemies, most of which are demons. Some don’t have an exact weakness but in the list below containing all of the enemies we encountered, we’ve listed elements that they are not resistant too. For magic, you should typically be hitting 9999 at the moment anyway so a direct weakness isn’t always necessary.

Gelatin (Level 35)
Weaknesses: Royal Arms, Lightning

Galvanade (Level 54)
Weaknesses: Royal Arms, Guns, Machine Weapons, Blizzard
Notes: If you take too long to kill these they summon lots of Thunder Bombs. Dawn Hammer works to take them down quick.

Thunder Bomb (Level 38)
Weaknesses: Swords

Ereshkigal (Level 39)
Weaknesses: Fire, Royal Arms, Swords

Yojimbo (Level 45)
Weaknesses: Thunder

Bussemand (Level 34)
Weaknesses: Great Swords & Machinery

Red Giant (Level 42)
Weaknesses: N/A

Costlemark Tower Dungeon Guide – How To Get To The Boss

Once you reach the large, open space room with the squares on the floor. Do not activate the red switch, it will return you to the start. In the North East corner of the room inspect the glowing square on the floor to transport down to the room with the Red Giant. There’s a small hole you can crawl through here to get to the special door, but you cannot unlock that until the end of the game. Take the cube in the center of the room back up.

The next set of cubes is a puzzle. If you go in the wrong direction you will return to the Iron Giant room and face 2x Iron Giants and then 3x Iron Giants and a Nagarani, a near impossible fight at level 50. This is a really strange puzzle. I played through it several times and it felt different every time.

When you get back up take the North West most square, if it’s not available you may have to go South East again but it should be there. Take it down 2 levels. Once down, don’t go down again. Take the West cube. Kill the imps that spawn and then head South, kill the Bussemands and take the South East wall where they spawned. Then South and kill the Gelatins, then South again and kill the Bussemands, South again. Kill the Gelatins and Galvanade then East. Then click the one on the floor to go up. Kill Yojimbo.

Take the cube under Yojimbo and go back up. Kill the Imps and then take the East wall. Take down the Imps and the Galvanade and then the Southern floor, take it down twice. When you hit the floor take the Eastern wall, you’ll see a circle symbol on the floor. Kill the Bussemands and then take the floor down to go up. Follow the single path to Yojimbo with more Galvanade. Use the South wall, then East.

Drop down to kill the Gelatin. Progress, kill the Bussemands. Continue through to the boss.

Costlemark Tower Dungeon Guide – Boss Battles

Jabberwock (Level 58)
Weaknesses: Blizzard

This is actually a straight forward fight. Keep your distance and unload with Techniques and Blizzard spells. He does have an AoE Petrify that is nearly impossible to dodge so bring items with immunity if possible.

Costlemark Tower Dungeon Guide – Loot

There’s some decent loot in Costlemark, including 2 weapons that do increased damage to daemons and a Royal Arm, the Sword of the Tall – dropped by the boss.

  • Radiant Lance (On the floor in the second room past the Gelatin)
  • Thieves’ Way II (In the room with the Ereshkigal. Don’t cross the pipe, cross the ledge the opposite side)
  • The Good Chamberlain (Drop down from the Thieves Way II item and go through the large door on that level)
  • Platinum Bangle
  • Moogle Charm (Inside a room with a thunder node, the 2nd one)
  • Black Choker
  • Orichalcum (Cross over the beam near the start and check the top of the spiral)
  • Sword of the Tall Royal Arm
  • Requirement to obtain the Dungeon Seal Key that opens doors hidden in dungeons