I believe this one has been cracked for a while using Medieval shorthand and a few assumptions on some letters not being what they appear (C for G for example).
N D X O X C H W D R G H D X O R V I = + (in) NOMINE DOMINI CHRISTI OMNIPOTENTIS – CHRISTUS CUSTODIAT HONOREM WILLELMI,DOMINO NOSTRO GRATIAS HABENTIS – DOMINUS CHRISTUS, OMNIPOTENS REDEMPTOR, VINCIT (et) IMPERAT +
This one has been around some language and history sites for a while with a lot of study. The above seems to be the consensus and most logical translation. Not cryptography but a simple Latin dedication. You may recognize it as similar to a Catholic and Episcopal daily proper with a dedication as well to someone named William (probably the sword's owner).