为 冰封巨物 寻找最佳的先驱套牌，包括其胜率、热度，以及该牌在万智牌：竞技场中的合法赛制！
Defender
Thing in the Ice enters the battlefield with four ice counters on it.
Whenever you cast an instant or sorcery spell, remove an ice counter from Thing in the Ice. Then if it has no ice counters on it, transform it.
