I've been fine with Blood Sword only being used for OTing or pure DPS mode. The trick is establish hate, then turn Darkness off. They even tell you in the first quest to not delve too deep at once.

I do agree that the MP cost for Grit is way to high, it almost invalidates a full hit with siphon blade and Blood Sword on. I actually stopped dropping Grit for Blood Sword because of that.

Honestly the only thing that needs changing (imo) is the parry procs. I love procs; there exciting. However, Reprise needs to be a bit more reliable than it currently is. Maybe switch it so that Parry has a chance to refresh it, instead of making it available. A small QoL would also make a indicator when Low Blow is triggered. I've gotten better at watching for the parry itself, but a visual notice would help that much more.