― Blackbeard after stealing Whitebeard's power to add to his own (One Piece).
The ability to merge separate powers into a single whole and combine/merge powers to create combos or even to create a new force. Sub-power of Superpower Manipulation. Superpower variation of Amalgamation.
The user can merge two or more powers to create new powers as well as different combinations. Sometimes the second ability may be naturally born, on others it may have been taken from another by force.
The users can even use two or more separate powers simultaneously to use for various uses.
The Super-Skrull (Marvel Comics) has the combined powers of the original Fantastic Four in addition to conventional Skrull powers.
Rick Wilder/Combo Man (Marvel Comics) possessed marvel comics' superheroes and villains' powers and abilities.
Super-Adaptoid (Marvel Comics)
King Bowser Koopa (The Adventures of Super Mario Bros. 3) uses his "power pendant" to mix the powers of the Fire Flower, the Super Leaf, and the Kuribo's Shoe.
Master of Games (Teen Titans/DC Comics) absorbs the powers of heroes and villains.
Composite Man (DC Comics)
The Dragon Blade is able to mix both Water and Fire to summon the Fusion Dragon
Jade Chan/Amazing T-Girl (Jackie Chan Adventures)
Monster Kevin (Ben 10 Reboot)
Danny Fenton/Phantom (Danny Phantom)
Due to his hybrid nature, Ichigo Kurosaki (Bleach) can combine the unique powers of Hollows, Quincy, and Shinigami...
...Which is apparent with his dual bladed Zanpakutō, they of which contain separate powers: with the left blade, which is the smaller one, contains his Quincy powers, and the right blade, which is the larger one, contains his Shinigami & Hollow powers.
Due to having assimilated Kaien Shiba, Aaroniero Arruruerie (Bleach) can use Kaien's Shinigami powers on top of his own Hollow powers.
As an artificial hybrid meant to mimic what Ichigo naturally was, Hikone Ubuginu (Bleach) can also combine the various unique powers of Hollows, Quincy, and Shinigami to maximize their power and efficiency.
Clow Reed (Cardcaptor Sakura) combined both Eastern and Western magic to create the Clow Cards.
The One Being Sought (Code: Breaker) was born with the two abilities "Absolute Space" and "Cell Regeneration", granting him a powerful offense and defense.
Shigure (Code: Breaker) can manipulate "Ash" and use the "Giga Phantom" to increase his body parts size.
Hachiouji Saechika (Code: Breaker) can manipulate "Shadow" and "Effacement" to induce death around him.
Sasuke Uchiha (Naruto) transplanted his brother, Itachi's eyes into himself combining both of their individual Mangekyō Sharingan into a single and more powerful version in the form of Eternal Mangekyō Sharingan…
One For All (My Hero Academia) is a Quirk that lets one access enormous raw power that can strengthen its user. It was originally two Quirks that'd merged into one, a quirk that lets one stockpile power and an unknown quirk that could be passed onto another…
…aside from increasing in power as it was passed down, the inheritor's Quirks was added onto the the core of One For All, granting it six different Quirks thus far. Such as an nameless one, Fa Jin, Danger Sense, Blackwhip, Smokescreen, and Float.
All for One (My Hero Academia) is an ability theft based Quirk that allows its user to steal and stockpile countless Quirks, combining them in various different ways. Such as combining Muscle Coiling with Air Pressure and numerous attack power/strength augmentation abilities to magnify its destructive capacity.
Issei Hyodou (Highschool DxD) awaken the Diabolos Dragon Armour after combining the power of the Ouroboros Dragon and the Welsh Dragon into a single form.
Lord Drakkon's (Mighty Morphin Power Rangers) powers come from combining the Green Dragon and White Tiger Power Coins.
Deadpool/Weapon XI (X-Men Origins: Wolverine) was given various mutant abilities to become the ultimate Mutant Killer. If the surgery was completed he would have all of their strengths and none of their weakness.
God Rugal (Capcom vs. SNK 2) is the result of Rugal Bernstein combining his Orochi power with Akuma's Satsui no Hado.
The Egg Nega Wisp (Sonic Colors) can mix and match the different Wisp Color Powers.
Alex Mercer (Prototype) using both his blade and claws simultaneously.
Revan's mastery of the Force was so great that he could call upon the combined strength of both the light and dark sides of the Force.