Now, we're going to have some rules in place for Cero, so that no one spams them within a post. Here is how it is going to be. You can Cero twice in a single post, then you can't use it anymore. I've seen people spam a million Cero in one post before, and to be honest, I used to be one of those people once apon a time. So, I know exactly what I'm talking about here; you are allowed two Cero, then you have to wait one post for a cooldown before you may fire another Cero.
As for Cero, we have a rule for Gran Rey Cero as well. You must use a method similar to what Grimmjow Jaegerjaquez used in the manga/anime; mixing your blood with a regular Cero. Gran Rey Cero has a one post charge before it may be used, and afterwards, it has a three post cooldown. Only the Espada can use the Gran Rey Cero.
For Cero Oscuras, only the top four Espada may use it. It has a cooldown of six post, and can only be used after the Espada has released their Zanpakuto.