Photoshop Flowey

Photoshop Flowey as stated in the Neutral Route Credits, also known as Omega Flowey by fans and Flowey X in the game's code, is the entity formed when Flowey absorbs the six human SOULs at the end of a Neutral Route, serving as the final boss of that route.

Appearance
Photoshop Flowey takes on the appearance of a grotesque flower-shaped hybrid of plant tissue, human organs, and machine. Consisting entirely of realistic images, Photoshop Flowey is noticeably different from anything else in the game.

Photoshop Flowey's new body also strongly resembles that of the DT Extraction Machine's structure, albeit now filled with teeth, gums, and eyeballs. This machine was created by Alphys to extract Determination from the six previously captured human SOULs, the same SOULs that Photoshop Flowey would use to power himself.

Main Story
At the conclusion of the battle with Asgore, Flowey finishes off Asgore, and absorbs the six bottled human souls to increase his own strength. The game will then crash. When reopened, the typical introduction cutscene will glitch albeit with the second line changed to say "But one day, they all disappeared without a trace." and Asriel's appearance changed to a Loox, and the game will present the option to load a save file of Flowey's own creation.

In this SAVE, the protagonist stands in a space filled with nothing but emptiness. As they walk up, they find a save point, only to be greeted by the erasure of their save file, and a display of Flowey's face. Flowey will then gloat that because of the protagonist's idiocy, Asgore is dead, their save file is destroyed, and Flowey is now in control of the six human souls. He states that once he absorbs the seventh SOUL—the protagonist's—and becomes godlike, he will teach monsters, humans, and everyone else the "true meaning of this world": kill or be killed.

The protagonist is then thrust into a battle against Photoshop Flowey. This battle is not RPG-oriented, but instead based entirely as a bullet-hell encounter. Photoshop Flowey saves and loads during his attacks to disorient the protagonist. These include firing star-shaped projectiles from his eyes, launching numerous vines, flamethrowers, finger guns, pulling in flies, dropping bombs, lasers, and using the weapons of the Six Humans. When Flowey activates the powers of one of his six human SOULs, that human SOUL will give an attack based on their associated objects and concepts.

During the attacks of the six human souls, the protagonist is able to call for help from each soul. After requesting assistance from each of the six SOULs, they will all encourage the protagonist to defeat Flowey, by healing you and reducing his defense to zero. The protagonist will then be given be able to effectively fight Flowey, until they reduce Photoshop Flowey's HP to zero.

However, when the protagonist does this, Photoshop Flowey simply loads a save file he used in the beginning of the fight to regain all his health, and then taunts the protagonist by repeatedly killing them and then reloading the save file. Flowey then encircles the protagonist's soul with bullets, much like he did in the beginning of the game, and invites the protagonist to call for help. Nothing happens, and Flowey proceeds to attempt to destroy the protagonist, but his attack mysteriously disappears, and the protagonist's HP is refilled. Flowey then attempts to load an alternate save file, but finds that he cannot.

The human souls then fight back against Flowey, draining him of his power, and reducing him to his regular form as a battered flower. Once doing so, the protagonist will have the option to either spare him, or kill him.

If the protagonist kills Flowey, he remarks "I knew you had it in you!" before dying; however, he returns to kill Asgore in a neutral route re-run, asking if they thought killing him would make a difference and states that he'll return when they load their SAVE. If the player spares him, Flowey insists that he hasn't changed at all, telling the protagonist that he will kill them and everyone they love if he is allowed to survive. After multiple spares, Flowey becomes confused and expresses frustration that he can not understand why they are being merciful, before running away.

In Battle

 * See Photoshop Flowey/In Battle

Trivia

 * Radiationgameover.gif text in Photoshop Flowey's GAME OVER screen is a reference to Toby Fox's EarthBound Halloween Hack. If the player loses to Dr. Andonuts, who is also a final boss, the game over text reads "Oh, [player name], it's all just a dream! Just kidding, you're dead forever," which is then followed by infinite looping "ha."
 * If the player runs into Flowey's pellets that surround their soul at the end of the battle, he'll reload file 6. Continuously running into them makes Flowey confused and has him tell the player to stop that.