Darkeater Midir is a very tough boss and you will have to face during the way subdue The Ringed City. To reach it, after opening the shortcut near the Ringed Inner Wall bonfire head down the lift and hop out to the door on your left that will appear on half way down the lift. From there go left and open the illusory wall to the right of the ember laying there. Drop down the ladder into the shrine area and then drop down the hole that you will find behind the altar.
There are two phases during defeating this boss:
- Close the gap between you and Midir as much as possible as well as try to avoid being shooted, multi-hit rampage from Midir and dodge rolling.
- Midir has a very large move set. If too close to the its head, you will be easily attacked by either a double claw swipe, which can easily be rolled through, or by goring you with his mouth, which is a little more difficult to see coming. It may also charge through you without warning, which for a glass cannon build could mean a one-hit kill. When Midir roars at you, it means it may telegraph this move.
- When things get too hectic up front, Midir will stand on its hind legs and shoot an AoE fire spell that will cover a lot of ground. If you have a strong fire-resistant shield, though, this is blessing in disguise by blocking the damage and going in for a quick strike or two.
- Falling back to some sort of distance will invite it use fire breath on you, or the AoE fire attack followed by a Dark beam that goes both straight ahead and sweeping across its front side, which is super damaging. Making it around to its back side doesn’t do you any favors, though, as it will use a tail swipe or tail stomp, so be careful when attacking its hind legs.
- In some cases, Midir will either jump backward to get away from you or fly into the air or carpet the arena with fire. If staying on its right side, you can avoid it and try to chase down the landing.
- Midir will perform a giant AoE Dark Blast at 50%. It means that the dragon hunkers down and gathers energy. At this time, you have to keep distance with it and pay attention to the rest of the fight because it can happen again.
- Another thing you need to take notice it that Midir summoning a swarm of Dark Affinity orbs, which can spook you into dumb mistakes. If you still stay close to them, you can use Midir’s body to absorb or roll out of the way from them in case you know their position.
- In this state, Midir will use Dark laser beam more often, but ditching the fire AoE buildup in favor of being a more focused attack. This can one-hit you, so be careful. If you can get back to its head, take some gratifyingly free shots since it takes it a while to recover.
Hope that the information above will help you defeating this boss easier.