Like all skills using magicka it scales off max magicka and spell damage. It is also affected by Bastion perk from Champion Points system.
This is not true. Actually all other shields apart from hardened ward and harness magicka scale of max health, while those two scale of max magicka. Spell damage doesn't influence any shield.Like all skills using magicka it scales off max magicka and spell damage. It is also affected by Bastion perk from Champion Points system.