Nantuko Calmer Proper Burial threshold seven cards graveyard magic

[Mint]

If I control a proper burial with six cards in my graveyard, and I sac him to destroy some enchantment, will the proper burial see him entering the graveyard as a 2/3 or 3/4?

[Arix]

Proper Burial uses the creature's last-known information to find out what its toughness was - in other words, whatever the creature's toughness was as it was last in play is how much life you gain. When it was last in play, the Calmer was a 2/3, so you gain 3 life.