The Elder Scrolls Online Guide: Banished Cells Dungeon Overview

Talk to Keeper Cirion after rescuing the Second Keeper. He will then tell you more about Rilis and the last keeper. He’ll come up of a plan that will take down Rilis.

Objective #3: Find Keeper Imiril
On your way to the third keeper, the Skeletal Destroyer awaits. This mini boss will spawn skeleton adds from time to time. He will also have random AOE that every group should be aware about. Have the healer focus on everyone’s health as that AOE can give a big amount of damage.

After rescuing Imiril, talk to Cirion again for the final preparation to defeat Rilis. Now, your objective is to find Rilis and slay him down.

Objective #4: Kill the Daedra around Rilis’ Binding Stone Prison
Before facing Rilis, you will have to fight mobs of Banished Sentinels. As with every other mob, this group of enemies can overwhelm everyone if the adds aren’t contained. Make sure DPS takes them down pronto.

Objective #5: Kill High Kinlord Rilis
The fight with Rilis is easy, as long as you know the rotation of his attacks. When fighting Rilis, the group must pay attention to the orbs that he spawns. As soon as the orb spawns, have everyone take it down. In addition to the orbs, Rilis loves launching some sort of a magical AOE blue fire around the battlefield. Simply evade it and you will eventually kill him.

As soon as Rilis is down, talk to Keeper Cirion to receive your reward.