Looking for some bitz advice.

What I need: a 28mm-scaled big-ass sword.  Bloodletter Hellblades are the perfect size, but this’ll be going on space marine (Belial, to be specific*), so they’re far too chaotic looking.  I’d been looking at using a sword from the Greatsword kit, but I don’t think that’s going to be heavy-duty enough.

Anyone have any ideas?

* Yes, I’m building a third Belial.  I’m okay with that.