Costlemark Tower

Navigate Costlemark Tower in final fantasy xv, finding the Radiant Lance and defeating Galvanades. Avoid the teleporting switch.

Inside the first room of Costlemark Tower, you'll face five level 35 Gelatins. They have resistances to physical, fire, and ice damage but only 5,000 HP. After defeating them, proceed to the next room where you'll encounter more Gelatins and dangerous Galvanades. Galvanades explode like Bombs but don't die, instead releasing smaller Bombs. Prioritize eliminating Galvanades to prevent them from overwhelming you. In this room, on the northern side, you can find a Radiant Lance.

The subsequent room contains level 39 Ereshkigals. They are weak to swords, shields, fire, and holy, but strong against lightning. This room offers two paths: southwest and southeast. Take the southeastern path first, crossing a narrow ledge to find the Thieves’ Way II accessory. Dropping down from this ledge leads to a door containing the The Good Chamberlain accessory for Ignis.

The other path involves balancing across a pillar and leads deeper into the dungeon. A staircase here will lead to a fight with level 44 Bussemands, which are similar to Hobgoblins. They are weak to greatswords, machinery, fire, and holy, and strong against lightning. After clearing the enemies, check the top of the staircase at the dead end for Orichalcum daggers.

Be aware that Bussemands may stay out of the battle area, making them unable to attack you. At the bottom of the staircase, fall out to be ambushed by Galvanades and Bussemands; focus on the Galvanades first. Loot the Mega Phoenix on the ground, then drop through the railing opening to face more Ereshkigals. After defeating them, pick up the Hi-Elixir. When you approach the door, the floor will crumble, leading you to another area with Bussemands and a Yojimbo. Defeat them all and collect the Platinum Bangle. Head north to find an ice-elemental deposit and another fork. Go west up the stairs to return to a previous floor. Take the eastern path to find more Bussemands and, in the northwest corner, an Oracle Ascension Coin.

Continue down the eastern hallway and take the first detour south, where two Ereshkigals will attack. Crawl through a hole to find another staircase with a Galvanade and Gelatins. At the bottom is a fire-elemental deposit, and at the top, you'll reconnect to the previous staircase. A dead end between the staircases, guarded by two Gelatins, contains a Mythril Shaft. Return to the hole and go east to a larger room to fight Ereshkigals and find a Durandal. Then, return to the staircase leading down.

Follow the only available path, encountering more Bussemands and an energy deposit for lightning magic. Next to it is a Moogle Charm. In the following room, a large downward slope is guarded by Galvanades and Ereshkigals. Defeat them and grab the Mega-Potion at the bottom. Continue along the path to a bridge with two Yojimbos and several Ereshkigals. Prioritize defeating the Yojimbos first due to their power. A Mega Phoenix is located next to the north doorway on the bridge, with another staircase beyond.

Descending the staircase will trigger a large number of Bussemands to drop down. Fight them off. You will eventually reach a large room with strange runes on the ground and an orange-red switch. Warning: Do NOT step on this switch, as it will teleport you back to the beginning of the dungeon.