Final form of the Great Katana Magian Trial weapon skill path, starting with Keitonotachi.
Unlike the nondescript Keitonotachi, this Great Katana actually looks both classy and unique, thanks to the other GKs that share this model (Kumokirimaru and Namioyogi) being extremely rare.
In additon: Tachi: Shoha's reported ftp jumps from 1.375 at 100% TP to 2.15 at 200% TP, allowing the TP bonus path GK to offer a fantastic 33% boost in Shoha damage, making it one of the better choices for Samurais without Relic/Mythic/Empyrean.
This GK is so underrated. You see all these SAMs getting Masamunes but then you only see them use Tachi: Shoha. If you aren't going to use Fudo and aren't gonna get the Aftermath then there really is no point on getting the Masamune other than "It looks cool!".
If all you're going to use is Shoha then this GK will do a lot more for your Shoha than the STR from the Masamune.