"
I have a hierophant with passive
Sanctuary of Thought which does not scale with ES increases, it just gives fixed amount of ES (15% of mana amount)
You are mistaken. Energy Shield modifiers definitely do apply to the conveted mana->es. Like with all things that use the conversion mechanics, it's also affected by modifiers to what it was (mana) and additive modifiers to either of these things apply additively. It's affected by increased mana and by increased energy shield, but those things are additive modifiers and will apply additively with each other.
