Hey there. This passive. It doesn’t works if you are on full health, but someone start first attack with ice storm for example. IMO it should work if any damage taken at full health, comparing to what this description says. (of course greatsword is equipped and not hided just for the record)
So summing up, you are on full health, someone starts with ice storm, you lose your hp, do NOT get fortify effect, and you are also not at full health to gain this effect from next incoming attack.
