Thank you for the clarification. And also, as far as I remember from battles, if an enemy casts something cheap, like Stone Skin or Shield, then part of their mana is not transferred to us. Is that correct?
Here's another thing about attack and defense differences – it might be useful to refresh your memory: >>>
MD(bas) = (Att-Def) * 0.05 * D(bas)
(if attack > defense), maximum 300%, i.e., the maximum damage will occur when the attack is greater than the defense by 60.
MD(bas) = (Att-Def) * 0.025 * D(bas)
(if attack < defense), maximum 70%, i.e., the minimum damage will occur when the defense exceeds the attack by 28 or more points.