Powerful doesn't always mean all-round good. When we see a great blademaster like Kas'im, we can say that he's powerful. When we see Palpatine uses Force Storm, we can say that he's powerful. And it seems that Maul prefer using the force to "empower" his body and use his rage and hate to create force fury. I make prediction like that because he never shows any use of force like sith lightning, but he won't be a sith if he can't use the force. I remember a picture, showing Maul withstands a Sith lightning. I think he's using force fury to withstand that pain. Anyway, there's no evidence Maul uses Sith Lightning, so I don't believe he can.
Most fun I've ever had with my clothes on!