Ap is a secondary stat on Ryze, not really that good on him. I`m more inclined towards Manamune PRECISELY because he is tanky enough as it is, WoTA, FH, RoA he`s still just as tanky as last patch, i simply choosed not to make him tankier, 6% magic damage scaling on mana is basically a DOUBLE scaling on his Q, too good to pass. I can reach 750 no problem. Trust me, it works, WAY better than a shield.