Flash

If this spell is casted before opponent's attack phase, this spell is an enchantment with "Non-flying creatures can't attack you or planeswalker you control unless their controller pays {X} for each creature they control that's attacking you."

If this spell is cast before your attack phase. this spell is an enchantment with "All creatures you control gains +X/+X until the end of turn. At the end of turn, Sacrifice Plant Growth."