Here is the Deathwatch Xenophase blade which is definitely not an alien artifact.

This is scaled to for a regular human at 800 mm long, with slots for 10 mm wide support rods down the center of the sword.

Feel free to alter and make this thing as you like

This is inspired by a sword in the deathwatch models made by Games workshop, and is a fan art piece.

Best of luck with this build, and may the emperor protect