Go-on Gold is a shinigami
"Break genkai" sounds suspiciously like a release phrase, doesn't it?Now, before you ask about his lack of sword, remember that only spiritually aware people would be able to see one.
A brief theory about Engine Sentai Go-onger.
I think Sosuke was originally going to remain dead until the GrandFinale, and GP36 would have ended with Yogostein killed permanently by the G12. Then, Sosuke would be replaced by a girl (an idea they didn't use until ''Shinkenger'') in the following episode, and then GP45 would have been played differently, with said new girl joining G3 Princess in place of Kegalesia (whose G3 Princess costume had red accents). They probably scrapped that idea due to popular demand, and tacked the last-minute SingleStrokeBattle between Sosuke and Yogostein onto the end of GP36.