- Location
- Australia
Just because we only see one person do Segunda Etapa doesn't mean it's not a Bankai equivalent. Remember that Bankai has been known to Soul Reapers for thousands of years, and its nature and the ways to achieve it are known and have proliferated. The Arrancars, in comparison, are a much newer organisation who, compared to the Soul Reapers, haven't had nearly as much time to experiment, develop techniques, and pass down traditions.Bankai is a logical progression of a Zanpakuto's release, well-known in Soul Society and treated as a teachable, repeatable feat that is more or less the gateway to Captain-level power. Segunda Etapa is a singular feat displayed by only one character in the entire manga.
The fact that Ulquiorra didn't even tell Aizen about Segunda Etapa also serves as an example of how averse Arrancars are to working with each other, so unlike with Soul Reapers, you're not going to find Arrancars working together to test the limits of their abilities. They'll instead all go at it alone, benefiting nothing from the skills, knowledge, and experience of other Arrancars that could help them along the way.
That would be hybridisation combined with Old Man Zangetsu no longer being able to suppress Ichigo's power.Visoreds have whatever the fuck Ichigo unlocked against Ulquiorra