So first I got all furor runes(crit dmg) and quints of desolation(armor pen). Recently I ran into a couple dodgy mofos and decided to switch out my yellows for evasion and it's really amusing to see a nice DODGE pop up. And now I'm considering replacing my blues for either more armor pen if its possible, or crit chance.

Just wondering what other master yi players do with their runebook. Also what do you guys think is more important for master yi, crit chance, crit dmg, armor pen, flat dmg... anything else?! Is dodge pointless on yi?

I've mostly been buying attack speed/crit chance/crit damage runes for Yi. Damage is kinda pointless for him because the amount is so low, its just better to get damage via items. Armor pen kinda works the same way. But that's just my personal preference.

I would not get attack speed on Yi. I suggest you keep your current page: armor pen is pretty amazingly epic. Also, crit dmg is very good as well; I like setting up my runes similarly to you.

If what you want is pure damage, here is the rule of thumb:

Armor Pen > crit chance/crit damage, but it's only available in Quints and Marks.
Crit Chance > Crit Damage if your Crit % with items is 30% without Infinity Edge or 50% with, else Crit Damage > Crit Chance.

Dodge is interesting, but I think it depends on your masteries and item build. If you have a 21/9/0 mastery with the dodge improvement and the 10% move speed on a dodge and regularly get Phantom Dancer early, they're probably worthwhile. Otherwise you're better with Crit Chance/Damage.

prob going to end up replacing the evasion for crit chance so that early game I'll be critting and critting hard at that

and if that goes well, who knows what I'll try next! all evasion runes?!