Immune means damage is not inflicted, even if non-preventable or outside combat.
100044
Ambrosius, The Ferryman
Unique wraith with 2 life. 1 strength, 0 bleed.
Ambrosius can move a retainer from your ash heap to a ready vampire you control and put 3 pathos counters on that retainer as an action. During your unlock phase, burn 1 pathos counter from that retainer. Remove the retainer from the game if it has no pathos counters. Ambrosius is immune to non-aggravated damage.
Rulings
Cards requiring a discipline come in play at the inferior version.
Requirements do not apply. If the cost is X (e.g. Reanimated Corpse), X is zero. If the effect puts/moves a minion into the ready region, that minion can act this turn.