So based on how the powers of all the major players in the series works, I had a theory, again this is purely conjecture so bear with me, ok so we know that Arrancar Zanpakutos are the nucleus of the their hollow powers contained within the sword, now with Ichigo's original powers when his internal hollow would take over he would gain access to all the standard hollow powers, albeit a highly beefed up version. So theoretically now that Ichigo's inner hollow has been forged within his bigger Zanpakuto it's possible that instead of a Bankai he has a Resurrecion where when released he could assume his hollow form and possibly control it now. Now on his smaller sword (his Quincy powers) it's possible that could be a Shinigami forged version of a Quincy spirit weapon and possibly Ichigo could have access to Vollstandig. Now here is some further evidence that may support this theory, now the only 2 known constant release Zanpakutos known are Kenpachi and Ichigo, however, as we recently discovered, even though Kenpachi's is constant release it still wasn't fully released until he called out his release command. Ichigo on the other hand hasn't shown any indication of having any kind of further Shikai release, and Arrancar Zanpakutos only have a single release. So long story short, I think it's possible that Ichigo may have sacrificed Bankai for Resurrecion and Vollstandig which in terms of this particular enemy may be more effective, or it's even possible that he has all 3 Bankai, Resurrecion, and Vollstandig.