Enemies who are enraged get increased health and damage. Killing them will spread the rage to other non-raged enemies.
Hero selection: All
Heavies, heavies, heavies. Not only do they seem to have double health when enraged, they also have double damage. The only real advice I can give here is to use this setup. It'll give you 2 healers, 3 damage amplifying abilities, with 2 of them being ults, 1 shield, 2 invicibility zones, and a **** ton of damage, which you WILL need.
Orisa for the shield and damage buffing ult. Baptiste for the healing, invincibilty, and damage buffing ult. Zenyatta for the healing, discord orb, and invincibilty ult. And finally Bastion, because he does a lot of damage.
Snipers are your priority here as they can destroy everyone including Orisa's shield in a heartbeat when enraged. Enforcers are also decently annoying but shouldn't be much of an issue with orb of discord and Bastion. Heavies are where the real problems are which I'll give a short guide on below for both areas;
When you get to the building go to the far right corner from where you enter and stay up there. You'll know you're in the right area as there'll be 3 entrances to the room. A hallway to the right, where no enemies came from in our run, the doorway in front where bastion can just lay fire, and a window to the right that can be ignored. The heavy will come from that doorway infront and this is where the invincibilty will come in handy. Use Zenyatta to tank the charge so the team can continue the bullet spree and then Baptiste drops his field to make sure no one drops. If someone happens to die here you can run out the window and go around after the tank has followed which'll give you enough time for a revive.
The hardest part being the castle area isn't that hard with enough abuse of the map layout. The 3 damage buff ults combined will do enough damage to kill just 1 heavy before it charges up the left hand staircase in the castle which is where you want to be. Kill the first heavy ASAP and if it does happen to charge Zenyatta can tank the blow with his ult once again to allow everyone to continue doing damage. When the second tank comes do as much damage as possible and jump off through the crack in the wall and make it over to the otherside (far right hand side of the castle if looking at it from the entrance) where you can run back to the staricase to kill any remaining enemies and the last heavy. This area is large enough to abuse the heavy and revive any fallen allies if it's needed, just make sure to watch out for enforcers while running from the heavy as they can still stop your run easily.
Thanks to Nico8912 for the video walkthrough using a simliar setup to mine. Which you can find below.
My teams setup:
Orisa, Bastion, Zenyatta, Baptiste.
Alternate setups:
Orisa, Bastion, Torbjorn, Baptiste.