Three Strikes Barrier (MP18-EN079) [2018 Mega-Tins Mega Pack]

If your opponent controls exactly 3 cards: Activate 1 of these effects;
<br>• This turn, your monsters cannot be destroyed by battle.
<br>• This turn, you take no battle damage.
<br>• This turn, each time your monster inflicts battle damage to your opponent, you gain the same amount of LP.