Ancient City - Rainbow Ruins (SGX1-ENF10) [Speed Duel GX: Duel Academy Box]

You must have this many "Crystal Beast" cards in your Spell & Trap Zone to activate and resolve these effects:
<br>• 1+: This card cannot be destroyed by card effects.
<br>• 2+: Once per turn, (including the opponent's) you can halve the battle damage you take.
<br>• 3+: When a Spell/Trap Card is activated: You can send 1 "Crystal Beast" monster you control to the GY; negate the activation and if you do, destroy it.
<br>• 4+: Once per turn, during your Main Phase: You can draw 1 card.
<br>• 5+: Once per turn, during your Main Phase: You can target 1 "Crystal Beast" card in your Spell & Trap Card Zone; Special Summon that target.