The Collector/5 BSC

"Time for your medicine!"

The Collector is the final boss in Dead Cells and can only be reached in the Observatory with 5 Boss Stem Cells activated. He is exclusive to the Rise of the Giant DLC.

Damage on a single hit is capped at 5% of his health.

Moveset
The Collector changes phases over the course of the fight. His two main phases use a different set of attacks. After taking enough damage, he will go invincible and teleport you and himself to a different room.

The phases typically go in the following order:

Melee -> Interim -> Ranged

The cycle will continue until he teleports to the final phase.

Drink potion
When the Collector's HP gets low (about 1/2), he will drink from the panacea, healing him back to full health and giving him significant damage/status effect resistance. If his HP drops below ~40% he will stun everything around him and gain a force field, which goes away after he restores his health. The second time it will be at around 60% and third time, 80%.

After the third time he drinks the potion, he will immediately transition to his final phase regardless of which phase he is currently in. In his 4th attempt, he will not be invincible, and attacking will cause him to drop the potion.

Melee phase
The Collector uses the following attacks:

The second time you get sent to this room, the Collector spawn a spike ball that bounces around the arena. The third time, there will be two spike balls.

Ranged phase
In this phase the Collector will use a different set of attacks:

The second time you are sent to this room, the walls in the arena will be covered by damaging enemy columns.

Interim phase
The player will be teleported to a room with three doors which will open and let a few enemies loose. During this phase some bombs will fall from above. This phase is the safest one by far.

The first time, he summons three early game enemies, and the second time he summons two mid game enemies.

Once all the enemies are defeated, he will teleport back to the arena and leave himself vulnerable for a few seconds. Afterwards, he will go invincible and teleport the player to the ranged phase again.

Final phase
The player will be teleported into a room with a giant telescope. In this phase, he will use every possible attack.

At ~80% HP, the Collector will drink his potion again, though he is not invincible during this period. If damaged, he drops the potion, which can be consumed for a massive stat boost. This allows the player to easily deplete the Collector's health and defeat him.

General

 * Crusher is highly effective against the Collector. It will slow him down greatly and will constantly interrupt some of his attacks like his tornado attack.
 * It is possible to root him with the Wolf Trap, which can shut down two of his melee attacks.
 * Giant Whistle can knock him up and prevent him from teleporting when he is about to leave. As the attack did not connect, its cool-down resets instantly. This can buy time for skills & mutations to recharge (Disengagement, Tonic, etc).
 * It also has the ability to interrupt some of his attacks.
 * If the Panacea has been consumed, it can be used to finish him in one hit.

Attacks

 * Try to attack in the air during his melee phase, that way, it'll give you some time to avoid his ground slam attack.
 * The safest way to dodge his syringe lunge attack is to cling onto the wall. It's also the best way to dodge both the ground slam and the bombs.
 * Avoid doing this in the final phase as the walls have spikes protruding from them.
 * For his spin attack, if you are cornered, roll towards the wall before he is about to hit you.
 * To dodge through his double tornado attack, roll through each column, then jump away and repeat.
 * It is possible to stay near to the Collector when he is using his double tornado attack. Dodge roll when he is about to send them, but be sure to go near him every time when the dodge roll stops.
 * Parrying the tornadoes is a valid option, but you will need some distance from the wall, especially if it does contact damage. Even without it, he can start using his beam attack right after and hit you with the spikes. Hold in the direction towards the Collector to minimize the distance knocked back.
 * He recalculates the orb attack per shot, so you will have to dodge at the last moment or parry it.
 * The orb attack is not recommended to parry, but if timed correctly, he can be hit after dodge rolling them.
 * His beam attack comes out fast with massive damage, but the interval is static.
 * For the beam attack, the visual cue is very subtle. Listen for the audio cue to time a dodge roll. However, dodge rolling when the yellow icon appears is usually effective.

Lore
When the Beheaded reaches this biome, the Collector reveals his plans to create the panacea, a fabled cure to all diseases, using all the cells collected by the Beheaded, further implying his true identity as the Alchemist. He asks the Beheaded to deposit them in the Catalyst next to him. Although the Collector doesn't believe the legends passed down by the first Alchemists of the island, he attempts this experiment in a last-ditch effort to cure the Malaise and save the island as well as himself. It turns out the remedy works, but it drives him mad with power, and lusting for more. Thus, the Collector attempts to kill the Beheaded so he would bring him more cells.

During the fight, which consists of a number of phases in different rooms, the Collector keeps healing by drinking the Panacea. Once he has taken enough damage, or the Beheaded has survived through all phases, the Collector teleports himself and the Beheaded in the last room. Then, he becomes vulnerable when he attempts to drink, and drops the Panacea when hit. The Beheaded can then pick up the Panacea. Once he drinks it, their attacks will become extremely powerful and quickly defeat the Collector.

As the Collector dies, he exclaims that what the Beheaded was doing ruined the island, and was therefore trying to revert his actions. The Beheaded ends the Collector by stomping his face three times, exclaiming pity as he walks away. It is at this moment that he realises that the cure is effective, and that he doomed the island's fate by killing the only person able to recreate it. Then, his body is vanquished by an unseen force, although his head remains. He proceeds to crawl away in a scuffle as the credits roll. After the run restarts the time keeper chides the beheaded and tries to correct the collector's death, unadvertedly causing a time paradox.

First encounter
The first time the player reaches the Observatory, the Collector will say the following:
 * "Welcome, my mute friend!"
 * "Do you like my Catalyst? Nothing too fancy really, but a necessary tool for any aspiring Alchemist."
 * "Never mind that... How many wretches did you slay this time? How many Cells did you bring me?"
 * "Would you be kind enough to put them in the Catalyst right there?"
 * "Are you familiar with the myth of the Panacea?"
 * "The cure to all disease..."
 * "... distilled from the crude essence of life itself."
 * "Well, if you believe the First Alchemists."
 * "Drivel! From a bunch of senile old fools. Fairy tales for gullible children... Just look at you."
 * "Dependence. Loss of empathy. Lust for violence. Insanity. Endless death."
 * "Nothing good can come of messing with Cells..."
 * "But then... I've already scoured the entire Island, scavenging from the remains of the fallen..."
 * "... And even the bellies of the living. Few were willing to help. Many begged for mercy."
 * "Is this all I've got left? The false hope of a bunch of children's stories..."
 * "Pathetic."
 * "Actually... This feels AWESOME!"

The first time the player reaches the Collector while wearing the King Outfit, he will say the following first:
 * "I see you've managed to crawl back into your own skin."

Any subsequent encounter will begin with this instead:
 * "Back again? And they say dogs are man's best friend!"
 * "Thank you for bringing me more! I was really starting to get the itch there!"
 * "Ah, that's better!"

Moments before beginning the fight, the Collector will always say the following:
 * "I've never felt anything quite like it!"
 * "Be a good sport and bring me some more... I'll send you back!"
 * "Time for your medicine!"

Fighting quotes
Throughout the fight, the Collector will randomly say any of the following:
 * "Go Back! Bring me more Cells!"
 * "Just a few more!"
 * "Don't be such a cheapskate! Share with your old pal!"
 * "Have you ever seen anything so beautiful?"
 * "Killjoy"
 * "Who's a good boy?"
 * "Bring me more, you wretched blob!"
 * "I need it! One last time!"

Fight finale

 * "You..."
 * "What have you done, moron..."
 * "I've been trying to save this wretched Kingdom..."
 * "Save it... From an ass like you!"
 * "Oh, we're all in deep now."
 * "Oh, we're all in deep now."

Kicking responses
After beating the Collector, he will say the following after being kicked:
 * "You can't kill me!"
 * "Urgh!"
 * "That's it? I didn't feel a thing."
 * "Ahhh!"
 * "Without me, you're nothing!"
 * "Ouch!"

After the third kick, he may say only one of the following:
 * "You really are incapable of settling a conflict peacefully, aren't you? Pity..."
 * "Not cool, mate! Not cool."
 * "Mommy!"
 * "I... I... I never noticed how cold these tiles are."
 * "Oh my god! They killed the Collector!"
 * "Your Princess is in another castle."
 * "Won't be needing a dentist anymore!"
 * "Git gu..."
 * "Where would you be without me?"

Trivia

 * Due to a visual oversight, when the Beheaded kicks the Collector's corpse, the syringe somehow moves in sync.
 * Even when the player is not wearing the Classic Outfit, the cut-scene where the Collector is killed will not change. The only exception is the King Outfit.
 * When the Beheaded kicks the Collector's face, the game may play a rubber ducky sound.
 * The quote "Oh my god! They killed the Collector!" quote is a reference to the responses said by Kyle and Stan in South Park when Kenny dies, specifically "Oh my god! They killed Kenny!"