When doing the CoE timeline, two updates exist in this zone:
First Piece: Click on the Ancient Stone Icon at ( -315, -9, -334 ) /waypoint -315, -9, -334(It is near the Shissar statues; out of aggro range of the named.)
Second Piece: Kill Prime Magnate Mrelg around ( 647, -159, -499 ) /waypoint 647, -159, -499.
Stay inside the circle, otherwise he will call for support! When he announces his AOE you must hide behind a statue. Kill his add!
You can also drag the boss around 1-2 corners back towards entrance and fight him there. You wont get hit by the massive AOE damage but you will get a lot of adds.
You may consider using one of the red charms on him that drop frequently in CoE advanced solo zones. These will take 30% of his HP and can be used more then once during the fight.
Focus DPS on the named. When adds come, move away a bit constantly and continue dps on boss. The adds are very slow, will follow, but don't let them catch up, or the boss will become very mean. If you have the heals you can heal through the adds and just burn the named.
This mob has an optional challenge mode. When he emotes, click on him (cursor turns into a hand), or right click him and select the only option that pops up to keep him from going into challenge mode.
During the fight snakes will come up from each of the ramps. They seem to stun.(how to prevent the stun? The stun says to cure before it procs, but the moment the snakes show up you get stunned before any debuffs show up to cure them)
"Wellspring" seems to be his most dangerous spell, try to interupt it everytime!
When you defeat him in Hardmode, you will get 3 crates of ethereal goodies instead of 1.
You may consider using one of the red charms on him that drop frequently in CoE advanced solo zones. These will take 30% of his HP, but will not work in challenge mode after an upcoming hotfix.