This one is complicated.
As for the movie thing, the movies are sort of another reality or alternate timeline, so they don't follow the rules of the universe right! My theory is right as they fused into base gogeta they powerd up in a blink of an eye. or they powered up because its the otherworld so it all freaky. Otherwise the buu saga make no sense...
Imagine the fusions are sandwiches. A peanut butter and jelly sandwich.
Fusion Dance is like taking peanut butter and Jelly, and mixing them together in a blender to make 1 new liquid. The fusion dance creates a new person, i.e. gotenkz is neither trunks or goten, or both combined, its someone else.
The poratar fusion is like a normal peanut butter and jelly sandwhich. Its both of the ingreidents, but they don't "mix" together. Its still 1 item, but they are seperate. A poratara fusion is half of one half of other. If you listen vegito is just goku and vegeta's voice layered over each other.
Gotenks voice is a totally new voice.
Now for the ss part.
Let's add soem sugar to peanut butter and jelly before mixing them in blender. They sure taste good seperatly mmm. Now we mix them in blender. Now the new liquid will still taste sugary. But it will be slightly less tasty as each one individually. Therefore, we can add sugar again.
Now let's take the pbj sandwich. We add sugar to each, then put them on bread. I take a bite. Eew, it tastes weierd. (This is like the ss fusion with earings which would kill them). This sandwich sucks! But i can't take away sugar(they stuck as ss). I can add more, but that makes it worse.
Now for dbz terms.
Fusion Dance-Combines 2 fighters of equal size and power into 1 person. The new person is completely new-new name, personality. The new person is in base form (non ss) when fused. By going ss, ss2, etc, you can create a more powerful fusion person. This means a ss fusion of trunks and goten would make the same person as a fusion as non ss trunsk and goten. But the ss fusion would have a person whose base power is equal to ss trunkspl + gotenpl
The non ss fusion would be just normal trunkspl+gotenpl.
Thus when the ss gotenks goes ss, its a much more powerful form of ss then everyone elses. In fact, he has so much power in his ss form, that he can go right to ss3.
My thoery is that if 2 giji ss fused they could go ss2.
Portara Fusion: Using mystical earings, 2 creatures are combined into 1 new creature no matter who/what they are. There form at the time of fusion will affect the base form of the fusion result. . If both people are ss, then the new fusion result will be in ss because both his orignal parts were.
Now the portara fusion woudl fuse them together like they are. That means they are in ss mode when fusion then they are ss as the new person. Since it drains ki and they are stuck as ss, they woudl die from the drain.
That's why fusion dance is more effective. You can fuse as ss3's, make a person whose base form is equal to both ss3 persons pl without the drain. They have all the power with none of the ki drain. Plus that person can go ss3.
So in conclusion, the fusion dance adds pl together, and ss form is a higher pl, making a stonger person. THey are not ss when fused, the person is always in base form.
Thats why ss4 fusion makes a guy who looks like he's ss4, but is not. The bodies of goku and vegeta are ss4. Thus he has the appearence of ss4, but is in his base form. He has the pl of ss4 added together, but can go ss4 himself too.
Very long...
As for the movie thing, the movies are sort of another reality or alternate timeline, so they don't follow the rules of the universe right! My theory is right as they fused into base gogeta they powerd up in a blink of an eye. or they powered up because its the otherworld so it all freaky. Otherwise the buu saga make no sense...
