Medieval Blockland needs more weapons other than just swords, right? Medieval is perhaps one of the most neglected time periods to even have decent add ons from other players.
So my suggestion is a tiny cannon that shoots cannon balls. It should probably have the same firing style as pirate cannon but a little faster.
I can't find any good pictures, so here is a fisher price pirate!

If you are going to copy this design you should make only one handle instead of two. That way you won't have to add hands to the weapon.