Kinda sad that yato s1 has potential but her s2 just so broken, just like Texas alter. Well texas s1 is very good againts that extra enemies in IS that stun you every attack and goes invisible, since texas s1 dot is quite big.
If you have Texas Alter raised, and M6'd like she should be (S2M3 and S3M3), then Yato Alter is also an M6 (S2M3 and S3M3). Yato Alter's S1 is filling the same niche as Texas Alter's S2, so if you already have access to that via Texas Alter then there's no need to expend the resources for it on Yato Alter. If you don't have Texas Alter raised, or only gave her S3M3 instead of properly M6'ing her for some reason, then Yato Alter is worth M9'ing.