[@Renny]

[quote=@Renny]
[@jynmi88] And the few that have the remarkable growth (if ever looking for some reason) could be the results of the Soul King's or to be even more vague, some metaphysical response to the appearance of the God-Tiered ones. Yhwach and his army, Ichigo and his friends, and the all around spike in power in The Soul Society.

Some kind of new breed or something like that.

Just a suggestion.  
[/quote]
I could see that being the case, especially if this will take place sometime after the events of the ending of Bleach.  However, I'm not too big of a fan of our characters being inherently more powerful that other shinigami.  Personally, I've always thought the biggest issue with bleach was instead of the characters focusing on using their skills to defeat their enemies a lot of it came down to power tiers(when the exception of Kenpachi).   I'd prefer some else like  maybe their souls are special so their blades don't ever  "complete" while residing in a zanpakuto, but instead are constantly, all be it very slowly, evolving new abilities or aspects?  

Although that probably is a case for more problems.