How to Beat the Demon Prince - Dark Souls III: The Ringed City

The Demon Prince

As the first, major obstacle in The Ringed City, the Demon Prince is a powerhouse. Upon first entering the arena, you immediately realize that your up against not one but two, slobbering demons. It's a tough but well-choreographed fight and you know you can pull through eventually. Finally, you fell the pair of beasts and wait for the satisfying accumulation of souls. But it takes too long. There's a growl and hiss and the last demon you killed reignites and massive wings erupt from it's back. Now, the true fight begins. The final form of this boss can be quite the challenge, especially since you have to deal with it after defeating the other two demons who are certainly not pushovers. The difficulty of this fight can vary widely depending on both the individual build and which demon you killed last in the first phase of the fight. The guide below is designed to acquaint you with the Demon Prince's move set and help you identify the openings that you have to counter attack. I will highlight these sections in red if you want to skim through more quickly. Good luck and thanks for reading.

Recommended Gear

• Light, High Fire Resistance Armor (Must be Able to Roll)
• Flame Stoneplate Ring
• High Poise Damage Weapon (You can stagger and riposte each demon)
• Grass Crest Shield (You should be two-handing your weapon and the stamina regen is nice)
• Hornet Ring
• Blooming Purple Moss Clumps
• 12+ Estus Flasks

Move Set and Recommended Reaction - Demon From Below; Demon in Pain

The first thing to know about these bosses is that they have two states. One state is aggressive and will pursue you with vicious melee attacks. The second is a ranged state where the demon will fire long range toxic effects at you. There will almost always be one demon in the aggressive state and one in the ranged state to balance their attacks. Occasionally, they'll both be in aggro state. You can recognize when one demon switches states by either them roaring and violently igniting in flames. This signifies that they're in the melee state. If they're in melee state and they do a two-handed slam AoE (area of effect) attack, the flames should extinguish from their body and they will then be in the ranged state.

Melee State

1. Multiple Swipe Charge - The demon can be at any range when they initiate this attack. They will violently swipe back and forth while moving forward rapidly. It will try to ram into you but the attack overall doesn't have the best tracking so just roll out of the way and let it pass by. Then run in for a quick attack on the back legs. If this does connect with you, it's extremely damaging so try and avoid it at all costs. You'll know the move is complete when it takes its left arm and scrapes it from left to right in front of you.
2. AoE Overhead Smash - The demon will rear up with both of its claws and smash the ground in front of him, detonating a small but highly damaging AoE burst of fire. This generally signifies that it's changing states. When it does this, avoid the AoE, and rush in afterwards to get in a bunch of free hits. Be aware though, if this demon is switching to ranged state, it's a fair bet the other one is changing into the melee state. Also, don't mistake the Two-Armed Overhead Smash for this because the demon recovers much more quickly after that move. If the flames brighten around the demon and he's only smashing directly in front of him, then that's the AoE Overhead Smash that you can punish.
3. Two-Armed Overhead Smash - Stretching out it's limbs, the demon will smash a large distance in front of him. This is highly damaging but easily telegraphed. Dodge right before it hits you. There's not much time to get in a counter hit however because the demon recovers relatively quickly afterwards.
4. Single Swipe - The demon will use either arm to swipe either left or right in front of him. If you roll backwards out of range, the demon will typically immediately reset and try a different move. 
5. Three-Swipe Combo - If the demon connects with the Single Swipe attack or you're close enough, it will continue a series of three horizontal swipes. After this completes, you can pull off a counter hit but it's a little tricky because of the quick reset. I recommend just backing off.
6. One-Armed Overhead Smash - The demon will quickly smash in front of him with its right arm. This is usually a part of a combo so its not a great time to strike. 

Ranged State

1. Toxic Breath - The demon will spray a large swath of the area in front of him with toxic gas. If you're able to trigger this attack and get behind the demon in time, you'll have a nice window to do three or four hits. Be warned though, don't try and cross the whole battlefield through the purple haze (Hendrix reference) or you'll become toxic which is a real pain in the ass.
2. Toxic Snake - Much like the Black Serpent pyromancy, a tracking snake of toxic geysers will closely follow you. If it hits you, it'll do light damage but it will also stagger you, which can be disastrous if you're trying to dodge the melee demon, and partially intoxicate you. The demon will fire this relatively quickly and generally only when you're far away. If you it coming, quickly dodge a couple of time either left or right.
3. Toxic Belch - The demon will quickly regurgitate a small series of toxic globules in an arc in front of him. This will raise your toxicity but is not very damaging. Just back off a few feet.
4. Toxic Spray - The demon will spray a relatively straight line of toxic that will stagger you and increase your toxicity. Dodge to the left or right.
5. Single Swipe - Unlike the melee version of this attack, the ranged state demon will only attack once and then attempt to retreat to gain distance on you. If you're able to chase it down, landing multiple hits is not too hard when it's in the ranged state. Just dodge correctly and watch for the occasional overhead smash.
6. Two-handed Overhead Smash - Identical to the attack of the melee demon mode but rather than pursuing you, the ranged demon will back off to gain range.

Strategy - Demon from Below and Demon in Pain

The strategy for these two is fairly straightforward but also dependent on the which state they're both in. If they're both in melee state, which is rare, then just back off and wait for one of them to change into ranged state. If they're both in ranged state, they're deceptively annoying because it becomes much easier to become intoxicated which will rapidly ravage your health. In this state, carefully plant hits on the closest one while keeping an eye out for its buddy's ranged toxic attacks. However, for the majority of the time you'll be facing a single demon in melee state and one in ranged state. The strategy for this is to try and balance the body of the melee demon on the body of the ranged demon, keeping it at bay. Once you see one transform into the ranged state, immediately try and put it between you and the demon. Then start smacking the ranged demon as it tries to escape. Usually, you can land two or three hits before the melee demon makes his way around. Just rinse and repeat. Follow the ranged demon, put it between you and the melee demon, whack it a few times, dodge the melee demon, and then get back to the ranged one. Furthermore, if you are able to stagger one of them, quickly run around to his head and perform a riposte. I would completely forgo the use of a shield in this fight as well as many of the attacks will simply tear through your stamina and they're too mobile to consistently block. If you manage to whittle down a single demon's health to about 25%, it's time to start thinking about which demon you want to kill first and last. I'll explain in further detail below.

Demon Prince - Move Set and Recommended Reaction

After you've defeated the two other demons, the Demon Prince will rise from whatever demon you killed last. Which demon you killed last has a huge impact on this fight so make it a conscious decision. If you kill the Demon in Pain last, the Demon Prince will get an unbelievably irritating meteor shower attack that deals major damage, breaks through any environmental barrier, and deals high damage. If you kill the Demon from Below, the Demon Prince will get a sweeping laser attack that's highly punishable but honestly, makes the fight a lot less interesting. The Demon Prince inherits a lot of the same attacks from his previous incarnations.

Killed the Demon in Pain Last

1. Meteor Shower - The Demon Prince will bellow fire into a massive fireball above his head and the unleash it in a large detonation sending approximately twenty, highly damaging meteors your way. They will break through any structures so don't try to hide just roll around like a maniac and if you get hit, DO NOT get up quickly. Let your character slowly get up and use the invincibility frames to your advantage. The best way to deal with this is to just charge him when he's casting it and try and stagger him out of the animation. If you do, he'll recover quickly but won't continue spawning that hellfire attack.
2. Floating Chaos Fireballs - The Demon Prince will spawn a pair of floating orbs that will rain three or four balls of fire on you every couple of seconds. It usually does this attack before attempting to cast his meteor shower. If this happens, tank the damage from the fireballs and try and stagger the Demon Prince out of the Meteor attack. 

Killed the Demon from Below Last

1. Laser Beam - The Demon from Below will leap away from you and slowly launch a sweeping laser across the arena. It's extremely damaging if you get hit by it but, it's also remarkably easy to punish. simply run over to him before the attack starts, get behind him and wail away at his extremities. You'll easily be able to take down a quarter of his health every time he does this attack. 
2. Laser AoE - After the Demon Prince completes his laser pattern, he will detonate a small vicinity around him. This attack actually doesn't do that much damage so it is better to simply block part of the damage with your shield or weapon and tank the rest.

Killed Either Demon Last

1. Flying Overhead Smash - The Demon Prince will soar into the air before crashing down on you from above with his claws in a fiery smash. Dodging this move is precarious at first but rewards the player able to pull it off. You'll want to roll when the Demon Prince is halfway down his smash trajectory. Afterwards, you'll be able to land a one or two hits. Alternatively, if you can't get the dodge timing down, blocking with the Grass Crest shield will negate most of the damage but also obliterate your stamina.
2. Multiple Swipe Charge - The Demon Prince will utilize the exact same attack as his predecessors with one very important difference. After he has charged, he will swoop around with a 180 swipe that will punish anyone trying to get in a late hit on him. DO NOT pursue him.
3. Flying Swipes - Occasionally, the Demon Prince will fly over your head and immediately swipe at you when he lands. If he takes to the air, be prepared to dodge as soon as he touches down.
4. Three-Swipe Combo - The exact same attack.
5. Two-Armed Overhead Smash - The exact same attack.
6. One-Armed Overhead Smash - The exact same attack.

Strategy - The Demon Prince

The Demon Prince brings a whole new bag of tricks to the fight and has an impressively deep health pool making him quite the opponent. The best thing to do in this fight, whether or not your fighting against the laser or meteor versions is to be aggressive. Stick close to him as much as you can, trying to angle your way around him. Occasionally, he'll launch an attack that will miss and you'll be able to punish him but only if you're close enough to quickly land a hit. Secondly, only attack once whenever he's recovering from one of his basic attacks. You must conserve your stamina and getting greedy will just get you killed. Thirdly, punish the big, unique attacks like the laser beam and the meteor shower as much as you can. The majority of damage that you're going to do in this fight comes from when the Demon Prince is winding up one of his major attacks. Finally, last but not least, is to consistently refill your health bar. If you're below 75% of your total health, chug an Estus. All of the Demon Prince's attacks do major damage so don't get one-shotted. If you're having a seriously rough go of it, try pulling out the Dragon Crest shield and blocking some of the attacks that you're getting hit by. It blocks most damage but will also cut down on the number of safe opportunities to attack because you'll out of stamina, thereby prolonging an already lengthy fight. Well that's all I got folks. Good luck out there and praise the sun!

Notes:

• In all likelihood, the arena that you fight the Demon Prince is Firelink Shrine from the original Dark Souls
• This is the only boss in the series that combines Toxic and Fire damage.
• You can summon Slave Knight Gael and Lapp for this fight.
• The Demon Prince's boss souls gets you a bad ass new pyromancy flame that doubles as flame scimitar.