Being a pure saiyan would be difficult to pull off, I'd imagine. But if it can be tastefully done and the character isn't too powerful compared to the rest of the cast then I see no problem in the idea. Though one has to bear in mind that Planet Vegeta was kinda blown up hundreds of years prior to this story and only a handful of saiyans managed to survive. Then one has to account for the saiyan family history and how they ended up on good ol' Earth.

Anyways, I've developed a character skeleton to use. I'll post it now so anyone can begin making characters on their own time, but I would like it if everyone waited to post their character until the OOC is up and running.

[hider=Character Sheet]
*picture here*
*any bits to add to appearance with words here*
[b]Name:[/b] (not a difficult one)
[I]Age:[/I] (minimum of 5yo)
[b]Race:[/b] (human, saiyan descendant, namekian, etc)
[I]Gender:[/I] (if it applies)

[b]Power Level:[/b] (idle/max)
[b]Stats[/b] (the max power level divided into four sections)
[I]Strength:[/I] (how hard they hit)
[I]Speed:[/I] (how fast they go)
[I]Endurance:[/I] (how much they can take)
[I]Ki:[/I] (how much energy they have, minimum 250 to fly)

[b]Techniques[/b] (a list of fighting techniques at their disposal, use the following technique format for custom techniques)
[I]Name:[/I] (easy)
[I]Type:[/I] (combination or ki attack)
[I]Description:[/I] (describe it)
[I]Required Power Level:[/I] (how strong someone has to be to perform it)

[b]Personality:[/b] (at least a good paragraph on how they behave)
[b]History:[/b] (at least two good paragraphs on their past)
[I]Other:[/I] (anything not included in the previous sections)
[/hider]

The stat system is very simple and loose, for a very good reason. They exist to allow easier comparisons between fighters but they aren't weighted so much that any combatant with a higher power level or higher stat than his foe will automatically beat said foe. As to how the power levels raise, and consequently the stats, it comes from actually fighting and training. After every fight, or sometimes during certain events in the middle of fights, the power level can raise. It is up to the player how to allocate the new stats granted by an increase in power, but it will be up to me (or any co-GM I might choose in the future) to determine the total points received. Even losing fights will increase the power level, though granted not as much as winning. Training sessions and timeskips will also grant points, the quantity also determined by me based on what the character does during that time. At the start, the acceptable power level range will be 200 to 700, with only two characters allowed to have 700. Naturally, the fighters will grow stronger as the story progresses and roles will shift. The weakest character probably won't stay the weakest forever and the strongest probably won't stay the strongest.

I'm also contemplating adding a "burst" power to the character sheet. The concept being that characters can attain a power level higher than their maximum temporarily, a burst of power. I'm iffy on that though because it would have to be limited in some way, which might very well render it to be a useless concept depending how it is limited. I'm open to suggestions on this one.

There are special rules regarding the different races. As there are technically loads of races in the universe, I'll only put down the special rules of the "common" races of Earth and if anyone decides to use something a bit more rare then it will be case-by-case.

[hider=Races]
Humans: The most common race of Planet Earth. Simple in design and function, most humans lack the ability to become legendary fighters. But for the humans that are strong, they have several advantages over other races. For starters, their ki regenerates at a faster rate than the other races and they can use what energy they have with better cost efficiency. As well, they are generally faster learners than the others and often more intelligent, though these advantages can vary (as some human fighters can be really stupid).

Saiyan Descendant: More human than saiyan, this breed of Earthling has an advantage over normal humans. Most notably that they tend to grow stronger faster and benefit from Zenkai. Generally faster and stronger than normal humans, though the difference is marginal due to how little saiyan blood they actually have.

Namekian: Originally from Planet Namek, most Namekians live on New Namek. A very slug/plant-like species. While they are also typically stronger than humans, their primary advantage comes from their amazing recovery ability. They can recover from wounds much faster than the other races, to the degree of growing lost limbs at the cost of some extra pain and energy. Stretchable body and limbs is also a plus, but Namekians generally burn through their energy faster due to their recovery speed and malleable body.

Majin: The pink, elastic race started by Majin Buu. Approximately as common as Namekians on Earth. Majin are known for their ability to take a beating and continue fighting, as well as having a completely stretchable body (unlike Namekians who have limits on that ability). Males are typically large and seemingly fat in nature whereas the females are smaller and thinner, though there are no differences in strength and speed across genders. Though far weaker than the original Majin, this race is typically more offensive than the other races. Due to the method of reproduction, Majin typically have less energy than the other races.

Anthro: While not exactly a species, Anthros are a category of species. Commonly seen in the canon, these are generally the "dog-men" and such. Due to their nature of being mostly humanoid, they can be capable of fighting just like humans or the other races. The most variable "race" of the common races in terms of appearance and abilities. The most common features include furry skin, tails, fangs, and claws. But some Anthros can have natural wings, negating the ki requirement for flight.

Demons/Aliens: Another broad category, much like Anthros. Wide in variety but mostly humanoid. They receive the same benefits are Anthros, though they have even more variability due to the broad spectrum of possibilities for creatures that do not have "normal" origins. Specific benefits will be determined on a case-by-case basis.
[/hider]

That covers some more of the basics, but if anyone has any questions feel free to ask.