It's a fun concept, but the power scaling is ridiculous. Comparing 10% of Ulquiorra's strength to a 10 million bounty pirate is off the mark. You do understand that even weaker Vasto Lordes could destroy a town with a weak Cero. Besides that, a normal human couldn't even stand in the presence of a normal Hollow. Ten percent of Ulquiorra’s strength, as a Vasto Lorde, scales way higher.
For example, let's take the current Luffy. If you take 10% of his strength and pit him against a 10 million bounty pirate, Luffy would easily stomp the guy to death. In other words, whether it's a 10 million bounty pirate or not, they are still normal people. They shouldn't be able to even withstand that level of Reiryoku or be in the presence of a Vasto Lorde.
I understand that you’re trying to balance the story somewhat, but you really should reconsider this aspect.
