Exorays are located in the tunnel on the way to the donut room (third tunnel from the left after drop) starting at (I-10) on the 1st map.
It is strongly recommended for all mages, paladins, and /nin to bring echo drops to combat silence gas. Tanks should keep exorays facing away from mages.
Exorays have a potent, ice-based move called Spore that causes paralysis, so mages are recommended to sub /whm.
This entrance can be reached by going through Beaucedine Glacier. Or by Lyco porting by trading the sparkling light a flower after unlocking the lyco port.
You will need 2 or more members of the party to control the plates that open doors.
At the first intersection at (J-8), go South. Head to the gate room at (H-9). You need to go through Odin's Gate (facing West), then continue North to (G-8). Someone must then flip a switch to open Shiva's Gate. Immediately on the right after you pass through Shiva's Gate is a switch that you can trigger to let the rest of your party through.
Once through the gate, head North to the center of the room at (G-8) and fall down hole marked A.
When you land, head east and you'll quickly reach Hume Bones area. There are 2 to 4 Liches available for pulling. Warning: Elemental danger. If you don't want to aggro elementals, you may camp in the large staircase between the Ka room and Lich room, but you will have to pull the Fallen Knights or Carby/jug pull the Liches under the effect of sneak.