Four

Superhuman speed: Four travels to the Sun in 12 seconds (≈45 billion km/h) in "Chapter Complete".
He is approximately 42× faster than light

Flight: Four can fly,

Superhuman intelligence: Four fluently understands multiple obscure languages, including Insulavoric, Morse code, and non-verbal communication from characters like Teardrop.

Superhuman hearing: Four can hear from extreme distances, including as far as the Sun.

Despawning: Four can remove contestants from existence by despawning them, indicated by a white flash or laser. In "B.F.B. = Back From Beginning", X uses a white laser eye beam to despawn Teardrop.

Screechy: Four can emit a screechy that stuns any targeted contestant. When expressing affection or excitement

Electricity Generation: Four can fire beams from their hands, electrocuting targets and reducing their health. They may need to charge up for more powerful beams, but can also shoot instantly.

Ultimate-level reality-warping: Four can manipulate most, if not all, aspects of existence, allowing them to do virtually anything.

Creation: Four can create items such as cakes, buttons, pillars, Paper Planes, Buzzer Boxes, soup, and jawbreakers from thin air.

Brain manipulation: In "What Do You Think of Roleplay?", Four swaps contestants’ personalities and bodies, which then shape-shift back into their original appearances.

Perspective violation: Four can defy 2D visual logic, appearing in front of and behind objects simultaneously.

Clouds manipulation: Four creates timers made of clouds to visually represent time limits during challenges

Mutilation: Four can abstractly deform contestants, effectively killing them, accompanied by a harp sound

Inception/Astral projection: Four can enter his own dimension to communicate with "EXITors", and still interact externally — suggesting inner space is larger or functions non-linearly.

Teleportation: Four can teleport when the number "4" is invoked and can teleport others with a snap. They also send contestants to the elimination space.

Possession: Four can possess objects like trees, buildings, and even the sun, which then turn blue.

Telekinesis: Four, like X, can levitate objects with a snap, shown in "The Game Has Changed".

Recovery: Four replaces Recovery Centers by reviving contestants with his hand, and even teaches X the skill. He can also recover others in unconventional ways, such as through jawbreakers.

Elimination: Four absorbs contestants for elimination, replacing previous devices like the Tiny Loser Chamber. He sends them to the EXIT, an alternate realm.

Battle for BFB, also known as BFB Post-Split, is the second part of the fourth season of the Battle for Dream Island series. It premiered on Friday, April 17, 2020, with the release of "X Marks the Spot", and concluded on April 9, 2021, with the release of "Chapter Complete".

The prize used to be just a BFB, but in "X Marks the Spot", Four added the original prize (a BFDI) back to the prize pool, making BFB the first season to have two prizes.

Battle for BFDI goes back to the traditional format of challenges and eliminations, similar to the first and second seasons. While the season starts with viewers voting to eliminate a character as per usual, the elimination style changed to a choice of saving rather than eliminating in "X Marks the Spot".

This season utilizes a hand-drawn art style that uses drawn limbs and faces rather than reusable assets like every previous season. For the first few episodes, the animation was very simplistic which allowed for longer episodes to be made in a shorter time, but by the time "Return of the Rocket Ship" was released, the style became way more polished which became the staple art style the show would use for all future in-universe seasons thus far.

Many unexplained plot changes have happened that allowed for new characters to join the cast and for old characters to return. Additionally, Profily debuted as a contestant in "The Hidden Contestant".

The first episode, "Getting Teardrop to Talk", was released on November 3, 2017. It introduces the fourth season's cast as well as the new hosts, Four and X who originally come from a 2008 jacknjellify video called "X Finds Out His Value".

Four, as his name suggests, appears to be a blue Arabic numeral four (4), whose design is based on the version of "4" with an open top, most likely taken from the original Minesweeper. He is drawn simplistically and have limbs that are lighter colored. Like every algebralien, Four has four fingers.

Four is a very surreal number, with strange mannerisms, including being able to mutilate, revive, screech (causing either the stunning or death of the victim), shoot energy beams from his hands (causing the paralyzing and painful shock of the victim) or suck other characters into his body (sending them to the EXIT).

Whenever disgusted, he can have a more teal colored body.

During his time as a host, Four was shown to want a sense of dominance in the show, like in "Fortunate Ben," and gets furious if talked back to or has tasks done for him. When provoked, Four would show no mercy and would even do things such as dissemble close friends out of anger, even lacking remorse in the process. Four doesn’t tolerate criticism in early BFB, known to act with violence