a serious question

Okay so I have found tons of success on kassadin. Wether counter picking a Katarina or just playing it into a ap mid I win the match up with about 9-10 cspm and very high lane/roam pressure. So I was considering because I have almost every champion in the game and I been just buying runes lately. Some utility ones such as movement quints/lifestyle and all the things that help make some champions particularly better. With this in consideration I lack a good understand of the math and want some help with a specific kassadin rune page I wanna make and which is better.

Option 1: -magic pen reds -health per level yellows (I feel they scale well with buying rod) -6 cdr blues with 3 scaling mr per level -Ap quints

Option 2: -magic pen reds -scaling mana per level yellows -flat mana blues -Ap quints with the option of movement speed quints

How much damage does scaling yellows,/flat blues give cause you do scale with mana and that would make the scaling of rod more efficently but is it a actual damage increase or is option 1 better even though flat cdr runes may be a little weak. Hope for positive responses and I just wanna thank anyone who reads this and leaves constructive comments you rock