Fusionism

Summary
Fusionism refers to the ability to fuse anything together to create a new form. The user can fuse together objects, powers, emotions, concepts, living beings, etc., turning them into single unit.

Limitations

 * Not all fusions will lead to good results.
 * Fusing emotions might prove unstable or temporary.
 * May cause multiple sentient personalities the separate minds don't merge.

Users

 * Gems (Steven Universe)
 * Uses of the Potara earrings and Fusion Dance, as well as Namekians (Dragon Ball)
 * Various characters (Bobobo-bo Bo-bobo)
 * Dr. Doofenshmirtz (Phineas and Ferb); via Combine-inator
 * Feist (Archie's Sonic the Hedgehog)
 * Kirby (Kirby series)
 * Etcetera...