Which tier of Attribute Substitution is needed to be able to use the substituted attribute for Defend action rolls?
Tier I allows for the substituted attribute to be used for non-attack, non-invocation actions rolls. The Defend action is not considered an attack (See Defend Interrupt Action post). Therefore, is tier I sufficient to use the substituted attribute for Defend action rolls?
For example, a sorcerer has Attribute Substitution I (Presence->Protection). The concept is that his force of personality is so great that he can cause his enemies to hesitate when attacking. Can the sorcerer use his Presence score in place of his Protection score when using the Defend action?