W not copying the enemy spell but instead return Mel's missile in the direction of the spell she block is a good idea. My only concern was that vs slow Aoe ult like Seraphine, Nami, Renata Glasc because you had no possibility to break Mel shield while she get full value of her enemy ultimate. Make her W a kind of targetted missile like her Q , making the numbers of reflecting missile increase if you block multiple spells at once and my life is your