Help finding two specific engravings for Yasuke.

In order to beat the level 10 domain recently added, I have been trying to follow a build for Yasuke that relies on kills by posture attacks. I have the gear required, all I am missing is 2 engravings. The first is "+10% critical chance with posture attacks" which the game says should be sold by a merchant in the Mouth of Seta in Omi but the only merchant I see in the area is the port vendor who doesn't have it. The second engraving I am missing "+50% to negate projectiles" should be found in Katano Castle in Setsu but I have looted all chests I could find there including a legendary chest and still nothing. Have I missed something or is there another way to get these specific engravings?