Leyline of Punishment

A player's "opening hand" is the hand of cards the player has after all players have taken mulligans. If players have any cards in hand that allow actions to be taken with them from a player's opening hand, the starting player takes all such actions first in any order, followed by each other player in turn order. Then the first turn begins.

If a cost includes life gain (like Invigorate's alternative cost does), that cost can't be paid.

If a creature is dealt lethal damage, it can still regenerate. If it does, the damage marked on it will be removed from it.