A family heirloom, given to the firstborn son of the Zwei family. When the owner of Zwohn settles down, he hangs it on the wall, waiting for his firstborn son to be of age.
When the son is ready to become a man, he goes through a trial of the family tradition. If he passes the trial, he will be gifted the Zwohn.

Zwohn (named after the sound that the sword makes when it's swung) is an unnatural heavy greatsword (8 lbs.), but to the owner, it weights as much as a longsword (4 lbs). The sword still requires two hands to handle, because it's badly balanced.

Greatsword: 
- Damage: 2d6 Slashing
- Twohanded

As a bonus action, you can speak the sword's command word to cause the sword arcane-split. The sword splits in two with an arcane flash of light, the two parts become identicals onesided shortswords (2 lbs each). Speaking the command word again, it arcane fused into the greatsword again. To do this you'll have to have both pieces in your hands and vice versa.
Zwohn have, when arcane fused, no lines or any indication of the sword being able to split.

Shortsword:
- Damage: 1d6 Piecing
- Finesse
- Light

On the blade of Zwohn, there are four runes, and only one of them appears activated. It glows with a very dim brownish light when drawn. The light isn't enough to be used as a light source. But the DM can give you disadvantage on your stealth check if the corresponding perception check is of sight.
The activated rune is written in ancient Dwarven script and means "Control" in Primordial, the language of the elements.

A person can only be attuned to Zwohn if it has been gifted to you by its previous owner. If the present owner should die, it's ownership returns to the previous owner. If no owner is left alive, it's ownership falls to its creator. This ownership deal is removed if its creator dies.

Proficiency with a Greatsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, present owner or its creator, Combat, Heavy, Two-Handed, Graze