How to beat the Oracle of Wael boss? (Forgotten Sanctum DLC)

[Sephyrias]

Talking about the second encounter, the one in Wael's body.
The first encounter was a cakewalk, but this one gives me a really hard time. Ran like 5-10 attempts, but never even came close to taking it down.

I'm playing at normal difficulty without level scaling. My team is at max level (20) and equipped with superb and partially legendary gear. The Oracle still shows 2 skull symbols.

The team comp is: Player Char (Cipher offtank), Ydwin (Rogue), Xoti (Priest), Aloth (Wizard), Fassina (Wizard).
I normally use Serafen (Cipher-Barbarian) instead of Fassina, but kept her in the group since the game recommends her for the DLC and I don't want to miss out on special interactions. Unfortunately, the game assigned all the skill points for Fassina automatically. I'd have rather made her learn Missile Salvo or Meteor Shower.

My strategy so far has been:
1. At the start, sneak up in stealth to cast Call of Rymrgand with Xoti, Missile Salvo with Aloth and Malignant Cloud with Fassina.
2. The fight starts. PC Cipher and Ydwin run up to take aggro. PC uses Borrowed Instinct to boost defense. Ydwin goes through the regular rogue dps skill rotation, then empowers for extra damage and does it again.
3. Xoti summons Muātu. Aloth casts 2 Delayed Fireballs. Fassina summons Writhing Tentacles to tank lasers.
4. Oracle drops to 80% HP and calls a bunch of max lvl wizard spirits. PC Cipher spends remaining Focus on Puppet Master and Silent Scream to cc some of the spirits. Ydwin goes after the rest.
5. Aloth empowers and casts Meteor Shower. Xoti casts Storm of Holy Fire on Oracle, Fassina casts Freezing Pillar on Oracle.
6. Aloth spams more Fireballs, Xoti casts Withdraw on whoever is dropping low HP from lasers or cures ailments. Fassina casts Chaotic Orb on the remaining spirits.
7. Oracle drops to 60% HP and calls for like 10 further adds, which then spam Killing Bolts, Fireballs and Tentacle summons everywhere.
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This is about as far as I get. All the extra adds end up knocking out my backline or frontline within seconds and it goes downhill from there.
I can get it down to "Hurt" at like 40% HP if I throw everything I have at it and ignore the adds, but I don't see myself winning that dps race any time soon.
At the same time, I also don't think I can win an endurance battle by killing all the adds first, since the Oracle's lasers deal so much damage and heavily reduce Xoti's healing.

Is there some way I can prevent the spirits or monster-adds from spawning?
Does destroying the machines in the corners do anything? I sent my Cipher and Ydwin after them during the initial attempts, but they have so much HP that by the time I managed to destroy one, the rest of my team was as good as dead.

[asnjas19]

Lower difficulty. Win. See story. Move on with yo life.

[dwarfpcfan]

If you go to a tavern you can retrain every party member and rebuild, by the time you reach the DLC you should be swimming with cash to spend on that.

With that said crowd control and debuff is the key. The eye is very weak to Wall of Many colors, gaze of the Adragan and the iike.

Load up on those spells, and since you have 9th level spells, get Minoletta's missle salvo for Aloth

Beyond that spam spells that inflict stun, paralysis and the like and you'll wittle it down to win

[Sephyrias]

Managed to beat it now.
Didn't change much about my strategy, except that I didn't bother with casting Meteor Shower, Storm of Holy Fire, or aoe healing spells.

Instead, I had Aloth cast Wall of Many Colors, then Missile Salvo, Delayed Fireballs, and then did it again with Empower when the Wall ran out.
The Cipher drained the Oracle's defense, but didn't get to do much else.
Xoti and Fassina both spent the whole fight summoning random things to tank lasers. The Oracle still got a laser on my melee Cipher at the start and Aloth later, but Xoti's Withdrawal saved them both and they both came back into the fight before it was over. Didn't really have to heal at all besides that.
This time I had Ydwin ignore the Oracle and go straight after the adds instead. Her damage output and cc was strong enough to make short work of them.

[MeanJim]

In addition to what dwarfpcfan said, you can disable the companion auto level in the options so you can manually level them up when they join. One of the imps in the main hall where Llengrath and Tayn are acts as an Inn where you can re-train characters.