Total No-Brainer

When Phage enters, if you didn't cast it from your hand, you lose the game. Whenever Phage deals combat damage to a creature, destroy that creature. It can't be regenerated. Whenever Phage deals combat damage to a player, that player loses the game.

Put target creature card from a graveyard onto the battlefield under your control. You lose life equal to that card's mana value.

Creatures entering don't cause abilities to trigger.