Talk:Illyasviel von Einzbern/@comment-31.17.106.231-20160920043030/@comment-122.55.57.66-20160921022954

Yeah. When you open up the Noble Phantasm option under Skill, you can combine duplicate cards to level up their NP level. In this case, your second Illya card will be used to strengthen the first Illya's NP. Afterwards, the second Ilya card will be gone. Which is fine because you can't field two of the same servant in the same team anyway so there would be no point to having duplicates (supports from your friend list don't count for this).

If you want to experiment to make sure you don't screw up, just use one of your others before Illya, like the Mephistopheles cards I see you have under your Illya cards.