I see a lot of people go 21 in the utility tree. I don't play Ryze though so i'm not sure how good, if at all, that is.
Going 9/0/21 allows Ryze to easily reach 40% CDR with just maxed Q and FH. It also allows him to level up faster then the other person in his lane when it is a stalemate which is a big advantage in mid. Then you also have the 15% reduction on Summoner Spells. Works out pretty well. --- Official Mienshao of the pokemon B/W and BW2 clans Comic pull list: UXF, WatX, Hawkeye, Avengers Academy, Defenders, Secret Avengers, Gambit, JLI, and Batwing