Board Thread:Questions and Answers/@comment-24593407-20140227000341/@comment-1387259-20140227020917

Well he does have Cero Metralleta, which is exclusive to his Resurección. If anything, it's known to be fast and that it fires multiple Cero at once. This would probably be his version of Oscuras (which is exclusive to Ulquiorra's Segunda Etapa). As for why he didn't use Gran Rey, I couldn't tell you.