Sworn enemy.

I've never played as them before, but a friend suggested I play as them against him. Question: How are luck and damage against sworn enemies related? The tournament is being played on the TE patch. Correct me if I'm wrong: If luck triggers +40% damage against sworn enemies, the damage will be 1.6*2. If only luck triggers, the damage will be 1.6. If only the 40% against sworn enemies triggers, the damage will be 2.0. Another question about the hero Anven. At the end of his description, it says that additional damage is dealt even if there is no critical hit, i.e., he simply has a 100% chance to deal additional damage against sworn enemies?