Percy has picked up that Zatanna is kind of bros with Annabeth, so that's automatically put her in a positive light for him. He's keen to get to know her better, especially because she doesn't seem to be blown away by his whole powers thing. They haven't really spoken enough for him to have too many concrete thoughts on her, but she seems like a good person that he could see himself becoming friends with, and he was legitimately glad that she is no longer sick :'D