i know that shinigami's kido abilities are determined by their kido and intel stats, but what exactly do hollows have? you see, shinigami have a quantitative way to measure their growth, spells to work for. hollows don't. i propose a system where a certain number of combined kido/intel points allows a Hollow to do different things with Ceros and Balas. for example, 25 combined points allows a hollow to fire Balas at high speed as Findor Carias did.
here is a list of other possible "landmarks"
Cero Doble, as performed by Nel
a much higher combined score would allow a Hollow to fire a Cero without charging it. (see Stark)
Gran Rey Cero, as performed by Grimmjow
Cero Oscuras, as performed by Ulquiorra
any other ideas can be of course posted. thanks