User blog comment:Marew/Need help beating oracle knights order vol.3/@comment-30654326-20161209013648

Okay mitigation is a must. I recommend Magress (though you should look into negating that light damage). Stein should also not be overlooked, as he has both mitigation, status removal, and barrier.

Barrier is the key to victory. For that, you have Stein. If you have the 2 turn mitigation build on him, even better.

You're going to want damage so that you can speed things up without getting your units destroyed (trust me, I would know). Rize.

You're going to want someone who can keep your units alive a LOT longer, so bring Zekt, Lara, or Rozalia (I recommend Zekt due to how insane Ark's damage can become at the second stage)

You can bring an angel idol unit. This is your failsafe if something goes wrong. Now, you could wait until Selena is at least 7 star for that angel idol ES, but if you can't wait you can try Ultor. HOWEVER, do NOT use his BB/SBB, since Yuura and Dion hit like a train.

If you don't bring an angel idol unit, Aurelia will probably be required so that you counteract Yuura's DoT and so you can proc ubb for chance to survive gate.

As for your friend, choose someone who can reduce damage taken by a considerable amount, like omni Ark. If you have any Zekt or Rozalia friends, you can use this to your advantage so that you can choose the other as your lead.

Just make sure that you don't lose any units, so bring as much angel idols and revives as you can. Don't forget to bring fujins along just in case.

The first battle, target Ark only. He's relatively squishy and you just need to hit him down to 50%. Afterwards, he will commit suicide after one or two turns.

Second battle, focus on Dion. Yuura and Ark are immortal (well, Yuura commits suicide later). Afterwards, Ark evolves and you need to survive 4 turns of living hell. Then he commits suicide, and if you have barrier up, you're safe (unless your HP is mad small, which would be your own fault).

Literally, this whole fight is waiting until they commit suicide. That's it.