The mighty Certus is 225% better than a typical shortsword, partly because its faster speed. It is much heavier than a shortsword. You will take quite some skill with bows to use it well. Take care, this is one-of-a-kind. 885% better than a typical shortsword after +7 enchant.
It is unique and therefore you can only wish for one, it should be wished for like this:
blessed immutable +3 Certus
Appears to be a "Bladed Bow", but when worn, it generates a white glow.