The only two characters that are able to appear as clones due to their speed are Yoruichi and Zommari. As long as their speed is not abused on the site, this rule will remain this way.
As another part of the rule, I don't give a flying rats ass if these two characters can do it. Your CUSTOM character will not be allowed to do this. End of story. There will be no arguments against this. You have an OC character because they are supposed to be ORIGINAL hence the 'O' part. By trying to say that a canon can use it so you should be able to takes that away.
The limit to the clones is set to five clones for both characters. As another added note, this does not qualify these characters as "untouchable" as some might say. They have both been show to have been hit. Zommari defeated by Byakuya quite easily and Yoruichi struck multiple times by Soi Fong.
However..this doesn't mean you cannot have an ABILITY that causes this senario. Though it would be weakened and moderated to make sure nothing unfair started happening. This is just to say that you can't do this because you are just that fast. Only those two characters are "fast" enough to do this without an ability.
Well, I think that is it. If there is something that I left out that you think should be added, and I don't mean arguing with the rule because it is staying, please let me know.