With respect to the yuki-onna/ice lady boss, it is indeed surprising just how many bosses can be simply status debilated and then shot/bombed to death
Was weird adjusting at first considering the Ninja Gaiden games typically utilize projectiles as stun tools (except for the unbalanced projectile UT's in vanilla NG2).
Sup xorthern. For an easier win against the blob, you can try the following:
1. use talismans to drastically lower its defense (and its attack if you like)
2. you can also inflict a status ailment like burn on it via bombs, fire talismans, and living weapon attack talismans
3. shoot it to death with the cannon firearm/use your living weapon guardian spirit mode to steal the fight if need be