Caster's curses were "realized spells," something along the lines of a Sarda-style "Make Shirou Come to Me" personalized spell.
Most magi use more freeform "liquid spells" or "prana manipulation" to interfere with people's minds. That sort of thing can be washed away with prana.
Trying to wash away a solidified spell is like trying to wash away a fireball - the thing exists, it's too late.
Most magi use more freeform "liquid spells" or "prana manipulation" to interfere with people's minds. That sort of thing can be washed away with prana.
Trying to wash away a solidified spell is like trying to wash away a fireball - the thing exists, it's too late.