Alright, well, here's the rule... It's quite simple...
Vizards are not allowed to use cero unless they have their hollow mask on. Also, they can not use sonido at all. I don't care if they do have their mask or not, NO SONIDO!
1) Sonido makes sound, shunpo is silent, why go for one with a sound?
2) Shinigami know to use shunpo first, why on earth would they learn to use sonido? That's just stupid.
3) Shinigami can't use cero, hollow can. Without the hollow mask, hollow powers cannot be used.
4) Vizard are NOT hollow. They simply have a hollow inside them. As such VIZARD cannot use garganta. I don't care how strong their hollow is. NO GARGANTA. The ONLY possible exception is if you have gained their FULL HOLLOW FORM. and only DURING THAT FORM may this power be used.
6.) Full hollow form IS NOT CONTROLLABLE it is simply a massive power upgrade that is the vizards highest form of power. Whatever your hollows personality is is what you would RP as. However if your hollow isn't a murdering killing machine then guess WHAT. It JUST became one. Congratulations.
5) I don't give a damn about internet rules and their there is an exception to all rules. These rules have ABSOLUTELY no exceptions.
by 
Subject: Vizard Rules 
