Multiple Lifelink Sources Create Separate Life-Gain Events If two Creatures with Lifelink deal combat damage at the same time, each one creates its own life-gain event
Flashing back an Opt with Snapcaster Mage may not seem like the exciting play, but its an important one to have in the bag, especially in matchups where you need to get aggressive like combo or Tron
Phasing out opposing creatures heavily disrupts their game plan, even if you just remove a key attacker or blocker
Unfortunately Starfield looks for the card's mana value and with both doors unlocked, the mana value of the enchantment is 0 and so it'd die and go to the graveyard because it has 0 toughness
Functionally, what this effect says is that if you can attack with The Lord Master of Hell, and you have 40 or more cards in your graveyard that are neither creatures nor lands, you win the game