Help with the mark "The Seer"

Where are the subterra's and how do i beat all three levels? I try to go on the elevator and it just takes me to the "Penumbra"...help please!

In each level of the Pharos subterra there are rooms to the NW, NE, SW and SE with pedestals in them, most of which join onto other rooms with monsters in. You basically have to kill these monsters for black orbs and place them on each pedestal. Once each pedestal is "fully activated", the elevator will take you to the next floor of the subterra.

The correct amount for each pedestal (in the order NE, NW, SE, SW) is as follows:

Penumbra : 18, 9, 3, 6
Umbra: 15, 9, 15, 18
Abyssal: 15, 21, 27, 12

The first monster you kill upon entering a room adjoining a pedestal room will drop a black orb, every 3rd monster thereafter will drop one. Any black orbs you miss go to a "massive black orb" that can contain really large amounts of normal black orbs.

ok so i'm lost, where is the subterra? it's not where you fight that horse mark is it?

Also, how to i get from the penumbra to the umbra or abyssal? And how many orbs to i put in each one, i see for Umbra you said 15,9,15,18, which is it?

The Penumbra, Umbra and Abyssal are the Subterra.

You move to the next level by placing the correct amount of orbs in each pedestal then heading over to the lift. The numbers I gave are for the pedestals in the following order: Northeast, Northwest, Southeast, Southwest.

ok so why r there 4 sets of numbers for each pedestal? and how do i beat phoenix?

There are four pedestals on each floor, he is giving you the numbers as NE, NW, SE, SW.

If you can't beat the Phoenix at this point, you are going to need to powerlevel your guys before picking a fight with the Seer unless you want totally destroyed. He will make you fight each of the Pharos' bosses (Pandaemonium, Slyt, Fenrir, Phoenix) one after the other before you are actually able to fight him proper.

Actually beating the Phoenix only really requires you to be competent with dealing with flying enemies.