How to Beat the Sundered Monarch
Details
Location: Bramis Castle
Resists: Fire, Ignition, Burn
Weakness: Bleed, Poison, Smite
Summons: Kukajin, Pieta, Tortured Prisoner
Rewards
Remembrance of the Sundered Monarch
10 Umbral Scourings
1 Vestige Seed
How to Beat
The Sundered Monarch the final boss in The Lies of P, not including ending-specific bosses. As such, he provides a suitable challenge, although the Sundered Monarch has one very substantial weakness that trivialises the fight.
That weakness is the Elegant Perfume. By rescuing the Tortured Prisoner and following her questline, you will be granted this special item that can be used from your hotbar as needed, once per rest. While seemingly useless throughout the rest of the game, the Elegant Perfume has a very special effect during the fight with the Sundered Monarch.
Using the Elegant Perfume during this boss fight will render the Sundered Monarch completely incapacitated for a significant amount of time. During this time, you can go all-out on him, and if your build is strong enough, damn near kill him in the time it takes him to recover.
Besides use of the Elegant Perfume, you will find that the Sundered Monarch does not put up as much of a challenge as you might have expected. His attacks have long wind-ups and long recoveries, making them easy to dodge and easy to punish.
The recommended strategy is to stay at a medium distance to the Sundered Monarch and bait out his big slam attacks. These have the highest recovery times, so dodging them and then getting your hits in should be easy enough.
You can also strafe around to your right, sticking close to the boss so that many of his attacks miss. He will, however, try to perform his sweeping combo, which got updated to deal more damage, extend the combo, and generally be a lot harder to dodge. If he starts performing this attack, just back away plenty and re-engage once he calms down a bit.
As long as you keep up the assault and you are careful about avoiding the big hits, the Sundered Monarch shouldn't provide as much as a challenge as his intimidating image would project.
When the Sundered Monarch is almost dead, fighting will cease, and he will make his way over to the statue to die. You can leave him to it and let him die of his own accord or speed it up by finishing him off - he won't fight back at this point.
Between the cooldown right at the end and the Elegant Perfume, you can actually avoid most of the fight and just enjoy whacking the boss almost to death.
Movepool
Swipe: The Sundered Monarch can attack with wide swipes with his hand, made more dangerous by the spikes sticking out of his arm. This can be done multiple times, and may be followed up by a dangerous spin. Dodge into the attack, or back away until the combo is done.
Jump Fire Slam: The Sundered Monarch will jump and slam down, creating a shockwave of fire that expands outwards, dealing high damage. Dodge forwards through the edge of the shockwave.
Jump Rock Slam: The Sundered Monarch will jump into the air and slam down with his rock, dealing damage in a wide area. Back away from the impact zone and dodge the landing.
Rain of Swords: The Sundered Monarch will wave his hand around in the air, causing flaming swords to begin dropping. This can be either, around the edge of the arena moving in, leaving the middle exposed, or from the middle outward, leaving the edge exposed.
Charge Attack: The Sundered Monarch will hold his rock in front while charging forward, dealing high damage to everything in his path. This has poor tracking, so sprint out of the way.
Throw Swords: The Sundered Monarch will tug at the swords stuck into his shoulder and throw them forward towards you, dealing high damage in a wide area. Dodge forward to avoid the damage.
Explosive Rage: The Sundered Monarch will rise into the air and explode, causing a massive shockwave through the arena that must be dodged forwards through. As soon as he slams to the ground, a second shockwave will blast through the arena that must also be dodged through.
Rock Slam with Swords: The Sundered Monarch will raise his rock high and slam it forwards with high range, causing swords to drop down in a line from the rock onwards as well. Dodge to the side.
Tracking Rain of Swords: The Sundered Monarch will channel swords into the air with a red glow. After he is done, swords will fall constantly for a long period of time at your location. Keep moving to avoid the damage.