text: Both the amount and types of mana you spend on {X} are taken into account while you're choosing a creature card from your hand. For example, if you spent {U}{U} on {X}, you can choose a creature card with mana cost {U}{U}, {1}{U}, {2}, or {W/U}{W/U}, among other possibilities, but not one that costs {2}{U} or one that costs {G}.