Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
The only way to play Ryze is to make his AP as high as possible. This build does that.
Ridiculously high AP so your spells do crazy damage
Good heath and mana so you can just stay out and kill forever
Low normal attack damage and critical chance but does it matter when your spells do so much damage.
No armor penetration but yet again this isn't a stat that you need