My favourite character theme is Xion‘s since it fits her character perfectly as the theme itself sounds nostalgic in my opinion and there is very short notes that sound kind of happy but are quickly replaced with sadder sounding notes. As mentioned previously I think it fits her character perfectly as the theme itself makes me think about how Xion wishes those moments were she would sit on the clocktower with her friends and have ice cream wouldnt end but knows it can’t as she will have give it all up in the end and have everyone forget her ( well at least she got her happy ending in KH3)