Яeverse is a phenomenon created by Void, in which a cardfighter loses his/her soul, and his/her energy becomes Void's. If a Яeversed fighter challenges a cardfighter to a cardfight and they win, the cardfighter who lost will also become Яeversed. Based on a statement by Takuto Tatsunagi, Яeversed fighters only challenge strong cardfighters in order to gain strength in quality, though judging from what is shown, sheer numbers are also boasted.
Яeverse fighters become malicious and obsessed with something their normal selves wanted but in much more extremes, for example, Kai's search for strength, Koutei's desire to become an emperor or Asaka's obsession with Ren. Their avatars also change into "Яeverse" forms of themselves, however in Kai and Suiko's case, instead they use the Link Joker clan. In addition, due to their personality change, their attitude in cardfights also change as they are stated to be much stronger than before. If they lose, they are returned to normal, their "Яeverse" card will disappear to inexistence and they will have no memory of what happened while they were Яeversed and, more importantly, who Яeversed them to begin with. Because of this, non-Яeversed characters have very little to go on when looking for clues. In a very rare occasion, they will retain core personality traits relating to their natural selves such as when Kourin, after seeing Aichi's determination, stopped her cardfight with him before attempting to finish him off.
Яeverse fighters also have a change in appearance. Namely, the aura they exude becomes black in color, and they gain red spikes beneath their eyes. With the stronger-willed of the Cardfighters, they can instead have a red highlight in their eye, rather than these spikes, but those with the spikes have only irises and whites. Those who lack the spikes instead have normal eyes and the highlight, as well as a shadow cast over their brow. Takuto, instead of either option, had a symbol appear on his forehead.
After Kai returns to Japan after Яeversing most of the world at this point, Яeverse Takuto revealed that cardfighters that become Яeversed become soldiers of the Link Joker clan. As these numbers grow, so do the strength of Link Joker eventually causing black rings to appear in concentrated areas of Яeversed cardfighters, which grow as more individuals in that area become Яeversed. Eventually, these black rings will grow to a point where it will eventually surround the Earth and engulf the world in darkness.
Яeverse fighters that are very skilled like Kai are able to:
- Defy Takuto's orders (Kai refused Takuto's order to fight Aichi Sendou)
- Create their own versions of Яeverse units (e.g. Dragonic Overlord, The "Яebirth")
- Retain their memories despite being released from the Яeversion
- Retain their "self-consciousness" while still being Яeversed (Kai admits to Aichi that he fully knows what he has done and is remorseless about it. Kai also plans to fight Takuto eventually to prevent himself getting controlled by the Void)
Known "Яeverse" Fighters
Brackets marked Яeversed Fighters that have been reverted to normal (defeated) and the Fighter(s) responsible for it, Similarly, Яeversed Fighters are marked with (Яeversed) by the Fighters responsible for turning them to Яeverse Fighters as well. All information are based on available footage from the anime series to date. This does not count the numerous unnamed fighters that have been Яeversed and thus this list only applies to important minor and major characters.
- Future Leon (defeated by the present Leon)
- Hitsue Middle School
- Eiji Saga (Яeversed by Rekka Corps Member, defeated)
- Reiji Uno (Яeversed by Rekka Corps Member, defeated)
- Kamui Katsuragi (Яeversed by Kourin Tatsunagi, defeated by Aichi Sendou)
- Miyaji High School
- Kourin Tatsunagi (defeated by Aichi Sendou)
- Shingo Komoi (Яeversed by Maki Nagashiro, defeated by Naoki Ishida)
- Naoki Ishida (Яeversed by Maki Nagashiro, defeated by Aichi Sendou)
- Eru Nakagami (Яeversed by Maki Nagashiro, defeated)
- Kongou Ikki (Яeversed by Maki Nagashiro, defeated by Naoki Ishida)
- Miyaji Middle School Cardfight Club
- Rekka Tatsunagi (defeated by Kamui Katsuragi)
- Miyaji High School Student Committee
- Maki Nagashiro (Яeversed by Void, defeated by Naoki Ishida)
- Taishi Miwa (Яeversed by Toshiki Kai, defeated by Misaki Tokura)
- Toshiki Kai (Яeversed by Link Joker in Takuto Tatsunagi's body)
- Team Asteroid (Fukuhara High School Cardfight Club)
- Asaka Narumi (Яeversed by Tetsu Shinjou, defeated by Ren Suzugamori)
- Tetsu Shinjou (Яeversed by Toshiki Kai, defeated by Ren Suzugamori)
- Suiko Tatsunagi (defeated by Ren Suzugamori)
- Team Asteroid Brilliant Stars
- Kiriya Bidou (Яeversed by Tetsu Shinjou, defeated by Kyou Yahagi)
- Hiromi Miyoji (Яeversed by Tetsu Shinjou, defeated by Team Avengers)
- Harumi Minami (Яeversed by Tetsu Shinjou, defeated by Team Avengers)
- Ayumu Mihama (Яeversed by Tetsu Shinjou, defeated by Team Avengers)
- Team Caesar
- Kenji Mitsusada (Яeversed by Toshiki Kai, defeated by Leon Soryu)
- Yuri Usui (Яeversed by Kenji Mitsusada, defeated by Kenji Mitsusada)
- Team Dreadnought
- Jillian Chen (Яeversed by Ali Pajeel, defeated by Kenji Mitsusada/Leon Soryu)
- Sharlene Chen (Яeversed by Lee Shenlon, defeated by Kenji Mitsusada/Leon Soryu)
- Team S.I.T. Genius
- Christopher Lo (Яeversed by Kenji Mitsusada, defeated by Kenji Mitsusada/Leon Soryu)
- Lee Shenlon (Яeversed by Kenji Mitsusada, defeated by Kenji Mitsusada/Leon Soryu)
- Ali Pajeel (Яeversed by Kenji Mitsusada, defeated by Kenji Mitsusada/Leon Soryu)
- Team Handsome
- Gouki Daimonji (Яeversed by Rekka Tatsunagi, defeated by Kamui Katsuragi)
- Kaoru Komatsubara (Яeversed by Rekka Tatsunagi, defeated by Gouki Daimonji/Nagisa Daimonji)
- Hiroshi Nakatsugawa (Яeversed by Rekka Tatsunagi, defeated by Gouki Daimonji/Nagisa Daimonji)
- Nagisa Daimonji (Яeversed by Rekka Tatsunagi, defeated by Ninja Master Neo)
- Underground Fighters
- Jun Mutsuki (Яeversed by Taishi Miwa, defeated by Taishi Miwa)