The strange trick here is that, it uses the pseudo-evasion thingy (where you actually heals the damage instead of reducing it) BEFORE the damage is taken i.e. at the beginning of the attack.
My question (to add): How do they even know how much the damage is while it hasn't even been taken (and heal it)?
darkRae said:BEFORE the damage is taken i.e. at the beginning of the attack