Board Thread:General Discussion/@comment-1970092-20160521174544/@comment-26091912-20160522053252

Well, he used a technique which looked like flames, but as you (should) know, no Zanpakuto uses two different elements. Getsuga Tenshou is an energy attack, so it would stand to reason that that other attack was also an energy attack.

Some people simply found it weird like when fighting Aizen, Isshin used Getsuga Tenshou without using his shikai. Which was shown Isshin doing it again when he entered Masaki's mind and slashed at the hollow mask that was gonna strike her with another Getsuga Tenshou, again not using Engetsu.

Yeah, and Toshiro has been shown firing ice in the same manner as his Shikai. Does that mean he can use ice techniques with his sealed sword? Probably not. Kubo probably just doesn't want to show characters releasing their swords constantly for every single instance.