Users can merge two or more separate objects into one, regardless whether the the objects are organic, inorganic, living, dead, technological, etc. User can decide which parts of the objects are dominant in the union, what are deleted and which merge.
Fuse Inorganic materials and create new substances with all the strengths and none of the weaknesses of their precedents.
Purple-Dyed Clown (Soul Eater, via Insanity Fusion)
Karn (Breath of Fire, with allies)
Harlan & Sven Kleinstock (Marvel Comics, through one another)
Digimons (Digimon series, via DNA Evolution and Digixros)
Bakugan (Bakugan series)
Twinrova (The Legend of Zelda)
Toa Kaita Wairuha and Akamai, fusions of Lewa, Gali, and Kopaka, and Tahu, Onua, and Pohatu respectively (Bionicle)
Lex Luthor/Brainiac (Justice League Unlimited)
Kyurem (Pokemon; via fusion with Zekrom or Reshiram through the DNA Splicers)
Mega Man.exe (Megaman Battle Network 4-6) via fusion with data from other Net Navi's with Double Soul or Cybeasts with Beast Out)
Super 17 (Dragon Ball GT) is a combination of Android 17 and Artificial 17.
Gogeta (Dragon Ball Z) is a fusion between Son Goku and Vegeta.
Mercury (Amalgam Comics) is a combination of Quicksilver (Marvel Comics) and Impulse (DC Comics)
Super Buu (Dragon Ball Z) after absorbing Piccolo, Gotenks and Son Gohan.
Wapol (One Piece) can merge anything he eats into his own body, or spit them out as a merged being.
Iblis (Sonic the Hedgehog), the raw strength, merges with...
Mephiles the Dark (Sonic the Hedgehog), the mind, to form...
...Solaris (Sonic the Hedgehog), the original being.
Koume and Kotake (The Legend of Zelda) merges to form...
Ichigo becoming one with Zangetsu and his Inner Hollow for the Final Getsuga Tensho
Parts of Tahu, Onua, and Pohatu are visible in Toa Kaita Akamai
Kyurem can combine with Zekrom to create Black Kyurem or Reshiram to create White Kyurem.
Iron Man + Green Lantern = Iron Lantern (Amalgam Comics)
When Hollow Ichigo takes full possession of Ichigo's body, the body undergoes a full transformation into a Hollow creature. He is granted with high-speed regeneration, enhanced strength, speed, durability and spiritual power, enhancing his Getsuga Tenshō, firing a Cero and having a extra appendage.
Ichigo's new Hollow Form. Granted with immense strength, durability, speed and spiritual power, enhancing his Cero, developed a Sonido and still has his high-speed regeneration ability.