Magic Weakness

Magic Weakness increases the magic damage a unit takes from spells and magical abilities. A unit with Magic Weakness has reduced magical resistance, causing spell-based attacks to deal amplified damage against them.

Magic Weakness is the magical equivalent of Fragile but specifically for spell damage. Apply it to enemies before unloading with your casters for amplified magic damage. On your cats, cleanse it quickly if facing magic-heavy enemies, as the increased intake can make their spells lethal. Physical damage is unaffected by Magic Weakness, so switching to physical attackers against Magic Weakness-applying enemies is a viable counter.