Ryze has been getting nerfs staggered about certain patches, and, while I haven't played him recently, I'm sure that they've done well to balance him out.
As for LeBlanc, it's sort of difficult to really objectively say much about her, but here's what I can recall best from base memory: Her damage across the board has been lowered, with slight damage buffs to her Sigil of Malice to compensate, alongside her being given the large-scale utility from her new Ult that requires some dedication to learn to use, as well as the ease of waveclear with the Sigil+Shatter Orb bounce.
On an honest, subjective note, I'm not sure why Riot added that pseudo-Spell Flux to LeBlanc's kit, but I can at least safely say that it notably differs in that it can only be used as a waveclear chain if LeBlanc spends her Distortion as well, whereas Ryze can keep casting Spell Flux on a single target and spread it to anything within bounce range.