Lle a Rhemen Ritual

Question

I have completed the two first parts to obtain the symbols, I put a character on each symbol and they are lit but nothing will happen now.

Did I miss something ?

Answer 1

On the level below (to get there you go through the hole to the left of the altar) there's a Nridek guy with spider army. If you kill him, you loot a Soul Vessel that's required for the ritual. The reward is Cladhaliath spear with the enchants dependent on your answers:

Stone Face on the Left:
  First answer: Increase weapons accuracy when attacking the same target as an ally
  Second answer: 20% of Grazes are converted to Hits
  Third answer: 1.2xDamage when below 50% endurance, +10 accuracy when below 50% endurance
  Fourth answer: 1.2xDamage vs targets which are stunned, prone or flanked
Stone Face on the Right:
  First answer: 20% of damage is drained as endurance
  Second answer: Weapon gets the "Exceptional" Quality enchantment
  Third answer: Increase accuracy of allies attacking the same target as wielder by 10
  Fourth answer: Attacks can stun on crit