Mitigation & Holy Defiance (Perk)

Which one goes first? Does the damage get reduced to 35% and then reduced by mitigation or is mitigation useless with Holy Defiance?

Damage is mitigated by defense first, and the remaining amount of considered for Holy Defiance.

I was more refering to the character skill Mitigation (damage reduction of 1% per point in the skill).
Will I, with that maxed, still take 35% of my max hp as damage or will it be reduced to 17.5%?

In that scenario, Holy Defiance would drop the damage down to 35% first, and then it would be further reduced by the Mitigation perk.

Awsome. Just the answer I was hoping for.