I would say to take a small detour from the Full AP Kassadin and pick a Hextech gun blade as well. Prenerf Kassadin was a Ranged threat now i consider him more a close range Threat than before. Duo to the Short cooldowns i can see people going more into the AD way. Manamune would be a good choice as well. The Overall Spell Damage might be quiet low but his Autoattacks will Hurt alot Thanks to Manamune, Hextech Gunblade and Lichbane, Including a Voidstaff and Rabbadons Deathcap and you deal enough damage to be a Overall Threat. Just my Opinion.

Im still experimenting with Tear of the Goddess but so far i've found that it doesn't help very much with using Riftwalk to escape. Making smarter plays and not having to spam Riftwalk always works out better than having to spam it to escape a tricky situation.

But, Tear of the Goddess and Archangel's Staff fall into that category of "its better to have it and not need it, than need it and not have it." Getting the tear early can weaken your laning harass but getting it too late will make the mana cap take longer than you want it to.

I will put it in the guide after i've had multiple major successes with it.
It's only a 2% of max mana, if more abilities scaled with mana like Ryze then i would build Tear of the Goddess every game no matter what.

I agree with this guy totally. Kassadin is pretty mana hungry, so he needs some mana regen and mana. His ult also scales with mana, so archangels would be a great choice. Otherwise the build is great :)

If Kassadins Riftwalk scales with mana now, and he has HUGE Mana costs, why wouldnt you take Tear???