MissStormCaller trnaslation about Aura been compared to Aizen:
- Aware of the fact that up till this point, the very moves Urahara had played, are the various tactics he had once employed against a Hōgyoku fused Aizen.
"There's no holding back. Let's give it everything we've got." However, that the Fullbringer known as Michibane Aura is a presence that demanded said degree of precaution, Hisagi had also understood this by now.
The narrator again compares Urahara's full incantation Hado 91 to be stronger than current Grimmjow's Gran Rey Cero who Kenpachi wanted to fight.
A cluster of light rays that are spread out in the sky converged before Urahara, forming a high density barrage it bores into the swarm of dark red dragons along with the surrounding atmosphere, burning them away. Oddly enough, it closely resembled the 'Gran Rey Cero' which Grimmjow and his company were unleashing at the same time in the Rukongai.
Even on the aspect of power, it is by no means outdone by Gran Rey Cero, perhaps the blow of a formidable Kidō even has the potential to surpass it.
In this translation it says that Aura didn't receive physical damage from Hado 91 she used her reiatsu and got weaker. IIRC I had read somewhere else that was holding back, maybe that was a bad translation.
"I see, is it that you're also able to manipulate the Reishi of my Kidō after all?" Finally, when the smoke before his eyes cleared away, a lone figure came into sight. As the remnants of what used to be the dark red dragons float around aimlessly in the surroundings, Michibane Aura was standing there flashing a smile that was as bold as ever. "No, if anything, it's like she controlled the soul within nitrogen and constructed it into a barrier… I guess that's how I'd describe it. Oh my, that you're able to do that in the Human World which has a weaker Reishi presence, it is truly an amazing thing."
'With an expression that said it was within expectation that she would not be shot down, Urahara observes Aura. "However, it would appear you couldn't very well get away with no damage." Although she had sustained no obvious external injuries to her body or garments, even Hisagi had sensed the change. Could it be that she had run out of reserve power to dilute her presence by means of Fullbring? Just a moment ago, her Reiatsu should have thinned out completely, but now it can be felt clearly even through Hisagi's Reiatsu Chikaku. Moreover, a fluctuation could be sensed in the Reiatsu itself similar in feeling to exhaustion, Hisagi had concluded that the woman before his eyes was beginning to lose room to manoeuvre. "Phew, that's a relief. If you were to tell me she was unscathed just now, then we would surely need to take measures on the level it took to deal with Aizen Sōsuke after all." "…This is Kidō? It's the first time I've been directly on the receiving end, but it certainly seems like a formidable technique. Looks like I have somewhat underestimated you Shinigami beings." —— I'd be worried if she's taking Urahara san's level as the standard to measure us by….