What level are you? I don't know this fight as well as some others, maybe I will try it again later. I've always been L20 when fighting it and didn't have problems. There are a lot of ways you could win this fight, but follow this strategy and you should definitely be fine.
The oracle is immune to interrupts and int/res/per afflictions, and resistant to mig/dex/con. So yes you can use gaze of the adragan which is downgraded to paralyze, but really this kind of fight is more about stacking buffs and defenses and then physically attacking, vs trying to put afflictions on him. Also keep in mind the oracle can target your will instead of deflection if it is lower (his abomination power), so watch for characters with low will.
I wouldn't bother destroying the devices. I mean you can, but to get frequent stuns you need to destroy all four. The oracle has low deflection and fortitude, so you want to hit it and cast spells targeting fortitude. It is particularly weak to pierce damage I believe.
You have two wizards. Are they both configured as casters? Wizards actually make excellent fighters.
I'd consider making Aloth a fighter. Give him Llengrath's Martial Mysteries or Katrenn's Grimoire plus Arkemyr's Illuminating Discoveries. You should start throwing down a wall of draining that hits the oracle and as many henchmen as possible, then cast every fast cast in Llengrath/Katrenn grimoire when the fight starts (Infuse with vital essence, spirit shield, deleterious alacrity of motion, llengrath's displaced image, ironskin, Arcane Reflection or llengrath's reflection, and llengrath's superior elemental bulwark), you can cast all of these in a couple seconds, follow with citzal's spirit lance and llengrath's safeguard, switch to arkemyr's grimoire, and cast arcane veil. Wall of Draining will build up these defensive buffs making Aloth quite hard to kill. You can use Arkemyr's Brilliant Departure if you need to escape or want to confuse things. The oracle is weak to pierce so Aloth would then just attack it repeatedly with the spirit lance. Throw up another wall of draining if your buffs are running out.
I'm not very familiar with fassina as a caster. But I'd have her cast Arcane Veil, Arcane Reflection, Caedebald's Blackbow, and then summon Essential and Substantial Phantoms (Essential is better), and the phantoms will attack with the powerful bow. Also the spell Pull of Eora is really useful for grouping enemies, it will pull Scavengers of Visions to it, just don't cast it on top of your guys unless they are immune to push/pull (hold the line talent, upright captain's belt). Minoletta's Precisely Piercing Burst will do a lot of damage also.
Give Eder a couple of high quality sabres (or your weapon of choice, lots of good choices) and have him fight the Oracle head on. You should have Unbending and its upgrades. This ability is far more powerful than it appears if the character is getting hit a lot, because each hit stacks with itself.
For your rogue, I'd just shoot the thing repeatedly with The Red Hand or Essence Interrupter with the hunting bow modal on. These weapons have extremely high DPS and do pierce.
And lastly Xoti should focus on buffing your party members. First summon the spiritual ally, it has unlimited heals and can let xoti focus on buffing and debuffing. Start with Devotions for the Faithful, spark the souls of the righteous, throw down a consecrated ground, use salvation of time to extend Aloth's buffs if necessary. Continue throwing down buffs like crowns for the faithful, Shields for the faithful, dire blessing, champion's boon. You can try to debuff the oracle's deflection with divine mark but the oracle has high will defense so I wouldn't bother. When there are no more buffs, cast damage spells like cleansing flame or storm of holy fire. Try to keep the spiritual ally as long as possible. Use withdraw as emergency cast on party members being shredded by lasers. You can also cast wall of thorns which targets fortitude and should sicken the oracle and weaken scavengers who hit it.
The soul mirrors can be really dangerous and depend how you've configured your characters, control them with maybe a pull of eora and a slicken or two, I'd ignore them and just focus down the oracle, then clean them up after he's down.