Ordalia di Eliod (Ordeal of Heliod) (it)
Enchantment - Aura
(CMC 2)
Enchant creature
Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Heliod.
When you sacrifice Ordeal of Heliod, you gain 10 life.