To fuse with someone using the fusion dance you have to first learn the Fusion Dance of course. Afterwards you find someone you want to fuse with that knows the Fusion Dance and who wants to fuse with you. When you fuse it lasts for 1 day. Decide who controls the fusion. When fused you have the attacks that you had plus your opponents. To figure out the power level and rest of the stats first look at the weaker persons stats. Multiply all their stats by 2 to figure out how strong you are. Here an example.

 

Goku                    Vegeta

Pl-5,400,000        Pl-4,800,000

Ki-4,800,000       Ki-3,800,000

Def-6,900,000     Def-5,100,000

Spd-5,500,000    Spd-4,000,000

Hp-5,000,000     Hp-3,900,000

 

Since Vegeta is weaker in power level they would multiply all his stats by 2. So the newly formed Gogeta's stats are now: Pl-9,600,000 Ki-7,600,000 Def-10,200,000 Spd-8,000,000 Hp-7,800,000

 

To do a Namekian Fusion the character that your fusing with has to be quitting the site because Namekian Fusions are permanent.You  need to learn the Namekian Fusion technique to do this. When you fuse like this your stats are doubled. You don't have to come up with a name. If I find out that you have to Namekians and quit with one just to get your stats doubled you will be kicked off the site for good.

 

This is almost exactly the same as the Namekian fusion. You have to have the Potara Earrings which are only available in Quests and Saga's.The person you are fusing with has to be quitting the site. When you fuse with him or her your have to make up a name and your stats will be doubled. Again if I find out you have 2 characters to double your stats you will be kicked off the site for good.