Trunkten

Gotenks' potara counterpart, he is antagonistic than heroic.

Appearance
The hair colors are inverted: Trunks' two bangs that hang down instead of Gotenks' widow's peak. Due to Goten and Trunks' hair colors being inverted, his eyebrows are not black like Gotenks' and have Trunks' hair color instead.

His clothing is a fusion of Goten and Trunks' clothing instead of the Metamoran clothing worn by his counterpart. He also wears a single Metamo-Ring (created from Goten and Trunks' Metamo-Rings fusing) on his left arm which allows him to remain fused as long as he wears it.

Power
He has the advantage of being able to remain fused as long as he wears his Metamo-Ring and can defuse at will by removing it. In Dragon Ball Fusions, he's classified as an A-Rank fusion.

Abilities
Galick Gun - Vegeta's signature Kamehameha-like energy wave acquired from Trunks.

Scissors Paper Rock Rush - A rush technique based upon Rock-Paper-Scissors invented by Grandpa Gohan and acquired from Goten.

Kamehameha - The signature energy wave technique of the Turtle School acquired from Goten.

Big Bang Attack - Vegeta's signature energy sphere technique acquired from Trunks.

Godlike Final Flash - Trunkten fires an extremely powerful Final Flash with godlike power.

Taunt - The user mocks the opponent to inflict Rage status which causes the enraged enemy to target the user. Special move acquired from Trunks.

Ki Pass - The user transfers their ki to a single ally increasing their Ki Orbs by two. Special move acquired from Goten.

Cover - The user uses their own body to shield an ally from Ki-based attacks. Special move acquired from Trunks.

Speed Up - The user Dragon Dashes in a zigzag pattern to increase SPD. Special Move acquired from Goten.

Bullet Rush - An energy barrage technique acquired from Goten.

Trivia

 * Trunkten is the only EX-Fusion to never require energy; even when using the Metamo-Rings for the first time, there is no energy cost. Presumably this is because they have such a history of fusing via Fusion Dance, and their friendship is so close, there is no need to use energy to assist with their affinity.