I converted both of my models. They were glued to their plastic bases and then I sculpted some tile texture over it with putty. The first was a minor conversion to be armed just with the powersword, like in the Filmation cartoon, without the shield or the empty scabbard. In the cartoon, the scabbard tended to appear when it was needed and disappear when it wasn't.
The second conversion was slightly more extensive. The powersword was cut off, and the hand was drilled, so the axe could be pinned into it. A new pommel was added under the hand with putty. In order to keep the powersword, I cut a plastic sword grip and crossbar from a sheathed sword from a Fireforge medieval men-at-arms set and glued it to the top of the empty scabbard, so my He-Man was complete.