Oathbreaker
Or
Oath Breaker
Hmm, the main idea sounds like this:
There is an interesting sword which someone (maybe a Samurai or the story can be placed in Medieval Europe or a fictional version of any of those) finds and canāt take their eyes of it.
That someone takes it (now, where that someone finds that sword, it can be anywhere) and finds himself (or herself or yeah, use your own imagination) in a hypnotic trance, heās glued to the sword.
Heās called to his duty (itās war time and the lord has made a call to all able men and women to do their duty and defend their homeland), his Lord summons him to defend his/their land from invaders, some savage neighboring tribes, which recently arrived in the vicinity, and he accepts, he answers the call, despite being a thief and a murderer.
YET, Why did he do it?
Why choose honor, when he didnāt live by any code of honor before?
What is the mysterious sword and why has it changed his heart?
Now, you can go anywhere and add a lot of stuff to this plot, make it much more complex, add some fictional history, some context to the place and time and the events and the characters presented hereā¦
About the Sword and The Title:
There used to live a warrior in the same land, a long time ago, and he lived by the code of honor of their land, he did not disappoint his ancestors, yet, one day he broke an oath and due to him not doing his duty, their land was pillaged, countless innocents died, and he never was the same from that day.
He pleaded with the Gods, to save his soul, and they sealed him in a sword fallen from The Heavens.
That sword should be used only for honorable purposes and it will create a special bond with its wielder, Strengthening them, to do their duty and never break their oaths.