Fusion is a technique used in the hit anime series
Dragonball Z and
Dragonball GT. Fusion can be done by anyone. There are 3 main ways this can be done. First, there is the fusion dance. This is done when 2 people, simultaneously and perfectly do a ritual dance. The two people are pulled together to form a new person that shares characteristics of both people, with an increased power level.
Goku &
Vegita, and
Goten &
Trunks perform this fusion.
Second, is the ring fusion. This is when two people wear magical earrings on opposite ears. They are similarly pulled together to form a new person with shared characteristics and improved power.
Goku &
Vegita, and
Supreme Kai and
Kibito perform this fusion.
Third, is a rare fusion, this is when one person is just transferred into another person. The person receives an increased power, but no physical changes are made, everything is done mentally and in
Ki.
Picollo &
Nail, and
Picollo &
Kami perform this fusion. With these fusions the end result has an increased power, and is able to learn new techniques and can gain a new style.