Main article: EX-Fusion
Metamo-Rings function similarly to Potara as they allow two people wearing a Metamo-Ring to fuse together. However unlike Potara Fusion, EX-Fusion requires the fusee to both wear a Metamo-Ring on their arm and perform the Fusion Dance in order to fuse, as opposed to Potara Fusion which occurs automatically without the need to dance once the conditions are met (with each fusee wearing the Potara on the opposite ear). Like Potara Fusion, the resulting fusion lacks Metamoran clothing and instead the two fusee's clothing also fuse together, however unlike Potara Fusion, the two Metamo-Rings fuse into a single Metamo-Ring which is worn by the resulting fusion. Interestingly, Tekka's EX-Fusions demonstrate that it is possible to change clothes while fused, though it is unclear how they do this without removing the Metamo-Ring which would cause them to defuse. When this single Metamo-Ring is removed by the EX-Fusion, then they will defuse. EX-Fusion can be performed even if by warriors with different body types and power levels, making it far more versatile that the Fusion Dance, another attribute it shares with Potara fusion. However unlike Potara or Fusion Dance, the fusee must have a strong affinity with one another to fuse successfully. As a result, EX-Fusion is easier to perform if the fusee have a close bond such as family members, best friends, master and student, trusted comrades/teammates, partners, or even rivals (like Tekka & Pinich or Goku and Vegeta). However, if certain conditions are met even mortal enemies can develop a strong enough affinity as shown by Goku and Broly, 17 and Cell, or Kid Goku and Zamasu.
In addition to affinity, EX-Fusion costs a certain amount of Energy (which is used to perform various actions in-game as well as functioning as currency). Tekka is unique as they can fuse with almost any recruited character, while canon and original characters (those exclusive to Fusions) can only fuse with certain individuals. Metamo-Rings appear on a table in the team's Spaceship where Tekka's Team can access the EX-Fusion menu to perform EX-Fusion or defuse an EX-Fusion. After performing EX-Fusion, the three Special Moves from either fusee can be added to the EX-Fusion Special Move list. After defusing, the Special Moves that the two fusee had before fusing must be added back into their Special Move list. Affinity (which are represented by a star in the menu) can be increased by completing specific tasks such the characters reaching a certain level, completing a story or sub-event, or other requirements. Besides Tekka, the Saiyan Pinich is the only character that originates in Fusions that can perform EX-Fusion with a canon character, his mentor Vegeta to form Pinita.
EX-Fusion notably allows people of different genders to fuse as Great Saiyaman 1 and Great Saiyaman 2 can fuse into Great Saiyaman 12, as well as the fusion of Android 17 and Android 18 who can fuse into Android 1718. Namekians also gain the gender of any gendered person they fuse with. As shown by Tekka, fusing with the opposite gender or Namekian results in the fusion being either male or female depending on Tekka's selected gender. In the case of 1718 and Great Saiyaman 12 both fusions are male.
Goku introduces EX-Fusion and the Metamo-Rings to Tekka's Team after sparring with them so they can train to face Cell at the end of Story Event: "Train with Goku!". Bulma assists Goku in his explanation, revealing that EX Fusion adds the power of the Supreme Kai's Potara Fusion with that of the Fusion Dance to create a new form of fusion that combines the strengths of both, as EX Fusion has no time limit like a Supreme Kai-based Potara Fusion, though uses Metamo-Rings and Fusion Dance in place of the Potara earrings, though can defuse at anytime by removing the Metamo-Ring. However she points out that the fusee must have a strong affinity in order to fuse correctly. After Bulma's explanation, Goku tells them to meet him back at the team's Spaceship so they can try it out. This leads to Story Event: "Back to Goku at the Ship!" where Tekka is asked to put on a Metamo-Ring and perform the Fusion Dance with any member of their team that that have strong affinity too (such as Kid Goku, Kid Trunks, Goten, Pan, or any other teammate they are capable of fusing with).
Goku reveals that Bulma invented the Metamo-Rings though after Tekka performs EX-Fusion with one of their teammates, Goku asks Bulma why she created the ring. Bulma explains that as Goku, Vegeta, Trunks, and Goten are not always around when she needs them, she decided to create the Metamo-Rings so she would have somebody tough around to protect her and the Earth. When Goku laughs it off, she reminds him that protecting the Earth is no laughing matter as it has been damaged many times in the past. It is implied that the events of Majin Buu conflict may have played a role in influencing its creation when she and the other Z Fighters found themselves inside the Timespace Rift. It is implied that Bulma did research into Potara Fusion knowledge which she combined with the data she had on the Fusion Dance technique (thanks to witnessing Goten and Trunks' fusion training under Goku and Piccolo) in order to develop it. Due to the presence of other EX-Fusions in the Timespace Rift, it is implied that Metamo-Rings have been marketed to fighters in the Timespace Rift. However this apparently allowed Frieza and Cell to discover the technology and EX-Fusion, leading to them using it to fuse into Celluza to defeat Pinich and Tekka who perform EX-Fusion as well to defeat the fused villain.
- The name Metamo-Ring seems to be a play on Metamoran and ring.
- Near the beginning of Dragon Ball Fusions, if Tekka returns to the Capsule Corporation at a certain point they can hear Bulma thinking up names for it.
- Humorously Goku mistakenly refers to it as mega-boring while telling Tekka's Team about EX-Fusion, only for Bulma to correct him. However Bulma herself ends up almost calling it mega-boring though manages to correct herself, causing Goku to glare at her for making the same mistake much to her embarrassment.