Shiva

Q. If I have 20 faceup cards in my evolve deck, can I play Shiva's "At the start of your end phase" ability?

A. No. Since you already have 20 faceup cards in your evolve deck, you would have no more facedown cards to pay the ability's cost with.

Q. My opponent has an Ancient Protector on the field and their leader has 2 or less defense. My Shiva's "At the start of your end phase" ability triggers, and I select their leader and deal it 2 damage. Also, the number of faceup cards in my evolve deck has now reached 20 or more. Does either the damage or Shiva's "you win the game" ability cause me to win the game?

A. No, the game continues. When an ability and an effect that restricts that ability are simultaneously in play, the restriction always takes precedence. In this case, Ancient Protector's "you can't lose the game, and opponents can't win" ability would prevent Shiva's "you win the game" ability. Additionally, because Shiva's damage and "you win the game" effect are part of the same ability, it would resolve in its entirety before moving on to the resolution of Ancient Protector's "When your leader's defense becomes 0 or less, put this card into its owner's cemetery and change your leader's defense to 1" ability.