I'm not sure. could depend on the matchup. The shield on his q only protects from magic damage so you may not want to max that first against an ad champion but i don't know.
I'm thinking it goes Q>W>E against most enemies but like i said, magic damage only blocked from the shield so i'm not sure.
q is good harassment though.
crystaline flask seems better since kass still has to wait until level 6 to do much. unless you have a good opportunity early, or i guess against someone who isn't much of a threat to you
catalyst the protector -> -> -> -> -> -> / (Depending on your needs)
I like maxing Q first against AP (versus ad I would never pick the new Kassadin), THen W as Lich Bane is core in my opinion now.
Ideal core build would be like:
Rush Tear of the Goddess
Then Rod of Ages
Then Lich Bane
Upgrade Tear
That is core IMO, next items would be:
Armor defense:
Frozen Heart (Option 1)
Zhonjas (Option 2)
MR:
I can only think of Abyssal Mask
Im a ***** D:
JK, this item is nice Guardian Angel
Moar Damagez:
Void Staff
Rabadons
Deathfire Grasp
I'm thinking it goes Q>W>E against most enemies but like i said, magic damage only blocked from the shield so i'm not sure.
q is good harassment though.
I build Tear > Roa > Athenes/lich bane > rabadons/void staff
Starting with either a ring or crystalline flask
maxing Q is pretty pointless because it doesn't even prevent you from getting cc'd E on the other hand provides slow and pretty high damage