1.請用正式名稱發問。我假設你說的白綠老頭是指
Gaddock Teeg
Noncreature spells with converted mana cost 4 or greater can't be played.
Noncreature spells with X in their mana costs can't be played.
Thorn of Amethyst
Noncreature spells cost 1 more to play.
2.答
Converted Mana Cost 看的就是指牌右上角的費用,不管你最後該付多少點。
所以只要非生物牌右上角的總魔法力費用小於4,不管你有幾個紫水晶刺都可以使用該非生物牌,而那牌的費用就是總魔法力費用+幾個紫水晶刺。