Legendary Swords: Gate Keeper

I have decided to draw a series of some swords. These are legendary weapons from one of my fantasy stories (means they are legendary in a fictional world I created).

This is the second one and also one of the most feared swords: The Gate Keeper.

Description: The sword of the chosen hero of the dark prophecy. He, who has to restore the world's energy, is cursed and blessed with this weapon. The sword sleeps in a black leather bracelet the chosen one wears, until it is called to battle. It has an own mind and it's wielder will never be it's master, but more a servant to it. The sword's task is to observe the chosen one and punish him, if he fails on his journey. But on the other hand, it has to protect him, too.
The blade is made from obsidian stone and decorated with enchanted gold that increases the powers of the sword.

Forged: 1000 years ago (by ancient gods)

Powers: The Gate Keeper's wielder is able to cast minor chaos magic and increase his natural physical strength by letting the sword temporary take over his body.