This Fusion is called the Dance Fusion. Telling by the name the major part of this fusion is to do a dance. The two fighters must do the dance perfectly or the Fusion will come out all wrong. If they do it successfully they become one stronger fighter. The new warrior has the combined strength of the two fighters. The only problem is that they don't get to use their full power. The two fighters could only use half of their power in this fusion.
This is the most powerful fusion out of the two. It is hundreds of times better than the Dance Fusion. For the fusion to work the two fighters must have a pair of Kaioushin ear-rings. The two fighters must put one ear-ring on opposite ears. This fusion is permanent but Goku and Vegeta were swallowed by Buu and somehow the fusion were off.