Ryze is now the better version of Cass

They are both pretty similar, both are Ap carries that scale into the lategame (though Ryze does it better). They both like to build Tear and Roa and build some items to be effective, but Ryze just does many things better than cass. He has arguably a very good laning phase, with that point click snare he can set up ganks pretty easily. He also has better ms bonus cuz passive and mastery and has an escape option with his ult. His cc is more reliable, he does imo more damage than cass and is way tankier than she is. No wonder he is been replacing Cassiopeia in the competitive scene lately.