Well, first you want to check the spelling. And you might want a shorter name, like 'Crescent Rose'.
Second, I'd take a cue from the Windblades. Swapping between an A3 transport and an A2 weapon is A4.
So make it a Grand Grimscythe with the ability to transform into a Behemoth Heartpiercer as a misc action (or freely for fun flurries), or, if guns are out, a small Essence Cannon. Very simple. And makes the ranged form less sad.