Alchemy

"Alchemy" is the avatar used by the god-like speedster Savitar to "prepare worlds for his arrival". The powers of Alchemy are bestowed upon a person that opens the Brahmastra, connected to Savitar and its ability to grant meta-human powers. While under the guise of Alchemy, those chosen by Savitar black out and do not remember their actions, waking up at a different place and a different time. While a person is forced to act as Alchemy, Savitar is able to speak through them to other people, particularly the followers of his cult and to various potential meta-humans, appearing in form of a word "Alchemy" on glass. Savitar has used different Alchemies for worlds that have come under his attention, but Julian Albert  in particular was chosen as the Alchemy of Earth One, after finding the Brahmastra in India.

Biography
Before his encounter with Barry Allen, Savitar has graced other universes with his presence, seeking out those who would dare to challenge him. As Savitar himself has gained powers from the Brahmastra, so did he use the stone to grant the powers of Alchemy to his acolytes, who would prepare worlds for their god's arrival. When Julian Albert, driven by the Brahmastra-conjured specters of his dead sister, went on an expedition to India in search for the artifact, believing that it would bring her back, he released the powers of Savitar on Earth One, blacking out after he opened the box, then waking up at a hotel, before hearing the news of his whole team's deaths. Fearing that he'd be blamed for those deaths, Desmond escaped to United States, where he continued to black out, mind controlled by Savitar, as he would put on the mask and act as Alchemy, high priest of the Cult of Savitar.

At some point, Alchemy transformed four individuals into meta-humans during a ceremony in glory of Dark Lord Savitar, leaving behind husks of skin from each individual. Among said individuals were Edward Clariss, Frankie Kane and "Shade".

As Alchemy, Savitar communicated with Edward Clariss, and led him to his lair, where he and his followers awaited him. Savitar also forced Clariss to remember his Flashpoint life and manipulated him into agreeing to serve him in exchange for restoring his powers, allowing Clariss to become "The Rival" again. After the Rival's first encounter with The Flash, Rival led Flash to a sawmill where Alchemy attacked Flash. Savitar's avatar claimed that he is helping people achieve their true potential to prepare the world, and had Rival fight Flash again. However, Rival was defeated by the joint efforts of Flash and Vibe. When Clariss was imprisoned, Savitar, known to Clariss only as Alchemy, scolded him for his incompetency and killed the speedster in his prison, though to the cameras, it was as if an invisible force thrashed Clariss around his cell before his death.

As Alchemy, Savitar later awakened another Flashpoint metahuman, Frankie Kane, recreating her Magenta persona as a split personality. After Magenta attacked her foster father and was confronted by the Flash at CCPD, Magenta came to Alchemy's lair, complaining that Frankie was fighting to gain control. Alchemy then told Magenta that once she showed Frankie's foster father that Magenta was in control, Frankie would fall in line. This led to Magenta's attempt to destroy the hospital her abusive foster father was in by throwing a tanker ship upon it, but the Flash managed to coax Frankie back to the surface, repressing Magenta.

In the wake of another failure, Savitar decided to target the Flash directly. Sending another of his transformed meta-humans, dubbed "Shade", to spread fear and panic and attract the Flash's attention, Savitar as Alchemy reached out to Wally West through dreams and visions, imploring West to seek him out so that he could restore Wally's Flashpoint powers. As the pain of Alchemy's visions worsened for Wally, Team Flash and the CCPD used West to infiltrate Alchemy's lair and then stormed it with the Flash's help. The Flash went to grab Alchemy's stone from a pillar but Alchemy's telekinesis stopped him from moving and summoned the stone to blast Flash repeatedly with beams of blue energy until it was shot out of his hand by Joe. Forced to his knees, Alchemy derided their efforts as the Flash moved to unmask him. Suddenly, an earthquake shook the lair and Alchemy bowed his head to the floor in reverence as a mysterious and unfathomably fast speedster slaughtered the CCPD cops and beat the Flash down. Meanwhile, Alchemy used his telepathy to reach Wally West once more and succeeded, turning him into a cocoon. His fast minion saw a distracted Flash and pinned him to the ceiling, declaring himself as Savitar, the god of speed. As this was happening, Alchemy got up, watching Savitar finish him off. As Alchemy bowed before Savitar and ran away from the scene, the Flash and Savitar fought across Central City, with the Flash losing badly, before help from Vibe and Killer Frost arrived and allowed to drive the "God of Speed" away. As Killer Frost questioned Savitar's Acolytes for ways to remove her meta-human powers, she eventually heard from Craig, after threatening him, that "Alchemy" was, in truth, but another acolyte, and the true power lied with Savitar himself all along. During Julian Albert's stay at the hospital, hurt by Killer Frost's attack, he suddenly heard the voice of Savitar and fell under the speedster's mind control, leaving the hospital to find the mask of Alchemy and serve his "god" once again.

Julian then kept the mask in his lab at Central City Police Department, when suddenly he heard Savitar's voice ordering him to become Alchemy again. As Alchemy and his cultists prepared to bring back every meta-human from Flashpoint with a massive ritual using the Philosopher's Stone, the Flashes of two world appeared, with Jay Garrick taking Savitar's attention, while Barry Allen went after the unprotected Alchemy, taking the Philosopher's Stone and bringing it back to its box. As the box closed, Savitar disappeared from reality, sealed away with the stone, and Alchemy's host, Julian Albert Desmond, lost consciousness. When Barry spoke to Julian, he revealed that he remembered nothing of his actions as Alchemy, and even refused to admit being turned into this criminal at first. Afterwards, Savitar tried to leave the Philosopher's Stone's box by, effectively, turning Cisco Ramon into his new Alchemy, using the same trick with a spectre of a dead sibling that he used on Julian before. Although Cisco released Savitar and was ready to attack Caitlin during a trance in which he thought he's seen his brother alive, Caitlin managed to persuade him to close the Philosopher's Stone box, trapping Savitar once again. As Team Flash accessed Julian's mind, seeing him as their last link to Savitar, the "God of Speed" spoke through Julian once again, telling Team Flash the truth behind Alchemy and his plans as whole.

Personality
As Alchemy is an extension of Savitar, every word he says actually comes from the meta-human speedster that he considers a god. When Savitar arrives on the scene to act independently from his pawn, Alchemy stops speaking altogether, while retaining the ability to fight off enemies or escape from them, until Savitar finds it fit to release Alchemy's host from his grasp.

Powers

 * Philosopher's Stone empowerment: While under the possession of Savitar, via the Philosopher's Stone, the hosts of Alchemy are able to use multiple powers; though it's unknown which ones are granted by the Brahmastra itself, and which ones are the powers of Savitar used through Alchemy.
 * Psychokinesis: Savitar carved the word "Alchemy" into mirrors and other surfaces without touching them, or even being present for that matter. However, it is implied that this may be a hallucination, as Iris wasn't able to see it when Wally was during while being called on by Alchemy. By extending his arm, he stopped Flash's super speed, keeping him in a standing position unable to move long enough to summon his Philosopher's Stone to his hand to blast him across the room. He then sent Flash sliding across the floor with a wave of his hand.
 * Retrocognition: Savitar is able to remember the Flashpoint timeline and is capable of making people, such as Edward Clariss, remember their alternate lives.
 * Telepathy: Through Alchemy, Savitar is able to communicate with anyone regardless of where they are.
 * Transmutation: Alchemy is able to biologically alter individuals to give them meta-human powers, the individuals leaving behind a "husk" in their place after being granted their powers. Acolyte Craig said that he can also take powers away from meta-humans, although whether this is true or not is up for debate.

Equipment

 * Brahmastra: Dr. Alchemy uses a stone to project concussive energy blasts that could send opponents flying through the air. It's unknown what it is made of. It also turns Alchemy's "chosen" ones into cocoons should they choose to reclaim their Flashpoint powers by touching it.

Behind the Scenes

 * Alchemy's role as an avatar, or a transmitter of Savitar's will can be likened to that of the Almebic, an alchemical apparatus used to transport essences from one source to another, which fits with the name.
 * Alchemy's mask slightly resembles that of a Plague doctor, as it has the classic beak-like part of the bottom.
 * In DC comics, Doctor Alchemy is the alter-ego of Albert Desmond who, due to a personality disorder, sometimes lapsed into a life of crime, using an object called the Philosopher's Stone to physically reshape objects into any form of matter he desired. One of his other villainous identities was "Mister Element", in which he could generate any chemical element to help him in his crimes. Additionally, after Desmond was cured of his personality disorder by Barry Allen, the Philosopher's Stone created a phantom construct Alchemy named "Alvin Desmond", that pretended to be Albert's twin brother. Desmond also had a number of successors, such as Alexander Petrov in the guise of Mister Element, and Curtis Engstrom in the guise of Dr. Alchemy. He also had a precursor named Zobar Zodiak, nicknamed "the Alchemist", who was one of the original wielders of the Philosopher's Stone.
 * Just like there has been multiple people using the title of Alchemy in the comics, so there were multiple people possessed by Savitar to act as Alchemy on different worlds of the multiverse.