Whew, this comment section is getting heated. And i mean in a bit of a bad way. too many requests for nerfs.
@Magnolia, i'm going to assume that since you said i essentially guessed the first phase of the quest, that this Katana is going to have a bad end as a potential route. In which Steele is killed by the blade when trying to wield it.
I'm also going to assume that you're going to add the requirement for high willpower, as wielding a cursed blade without high willpower is suicide at the very least. Meaning you are probably going to either add a character, or a manual that tells you a method of how to strengthen your willpower. I'm also going to hypothesize that this katana will be somewhat like the Tai e made by Ou Yezi, meaning the blade had a special method of forging that puzzles almost every scientist in the galaxy of the TiTS-verse.
as mentioned, since this is probably going to require training to wield, Steele will be provided a training weapon to practice withe before moving on to a real katana to practice with, before eventually moving on to use the Relic, but only by maintaining high willpower. Or by having someone suppress the the blade with qi, in which it's stats will go down considerably and it will also lose the "Ignores Shields" flag, but gain maybe 2 points of evasion.
As for my last assumption for now, i'm also going to assume that you're going to make it part of the quest that it explains how the crafting method has changed the blades material entirely, unintentionally making it so that it radiates a particular energy, similar go the Slut Ray which makes it able to bypass shields.
Does that sound about right?