Hey, Here is the challenge as a seperate challenge fic. I do not own Dragonball Z (this is one of the two challenge fics that do not have a starting chapter)
VIHAN FUSION
This challenge is where when they are young, Gohan and Videl meet, and somehow, with no one knowing, they learn how to use fusion together. This has the side effect of making Videl a demisaiyan like Gohan even when separated, and their fused form is female. You choose the name. The fused form is believed to be a stranger, and powerful, due to incidents like cell being dealt with by the fused form before leaving without talking to the others. The first time each Saiyan level is reached, including the one unlocked by the Elder kai, which is when the families learn about the fused form. When she helps each fusion to the others (Gotenks) and demonstrated together. There power is far stronger, together and they spend most of their time in fused form unless they need to see their families separately and school. And after it is discovered by the family then except school almost all of the time is fused. Also as to Pan, Gohan and Videl are the parents, but fused after the conception and are fused the entire pregnancy.
REQUIREMENTS
Gohan and Videl lean to fuse at an early age
The fusion makes Videl a demisaiyan even when separated
The fused form is female, you choose the name
They are the only ones who knows until they teach Gotenks to fuse
Everytime the reach a new power level they are already fused
Most of the time in fused form unless around, friends, family, and school
Things like Cell are defeated in fused form before leaving the area
Gohan and Videl are the only biological parents of Pan, but are fused the entire pregnancy
RECOMMENDED
Hercule Satan bashing
If you include one, then Gohan and Videl's fused form somehow become a Super Saiyan God/Goddess