Actually, I managed to ascend TamaCat without even trying. I just had her ascension materials, and at the time, I did not have any other Servants who needed them. I wanted to ascend Medusa, but Ushiwakamaru took priority. I don't have Vlad, D'eon, or EMIYA, and I don't care about Proto!Cu enough to do anything with him even though I have him. That being said, I managed to max out his NP because I keep drawing him in the Gacha.