While not a new item to the series (came out first in Smash 4) I really liked the Ore Club. I couldn't remember if it was original to Smash or appeared in another Nintendo game. I forgot it was in Kid Icarus: Uprising on 3DS.
While it doesn't appear to be much different from "sword" weapons, its biggest advantage is creating a tornado after a swing. The ore club really came in handy when I needed to take out most of the challenges in World of Light.
Even without the tornado, it's quite powerful. You don't want to be on the other end of this club, that's for sure.