That's my path, and I find it works very well.

Catalyst
L1 Boots
Catalyst > Rod of Ages (80AP)
Meijar's (140AP+80= 220AP)
Boots of Mobility or Mercury Threads
Zhonya's ((100+220)*1.25=400AP)

Buying Meijar's early is important so it can stack up to it's full potential, but the health/mana from RoA makes it a priority first.

At this point, it's a toss up based on who I'm fighting. Often I'll buy a Frozen Heart for the +armor and -cooldown. After that, I usually start chaining Elixir's of Brilliance. With Zhonya's, the 65 AP from the Elixir is increased to 81, putting you at a total of 481 AP.

Add to this that your cooldowns at this point are approximately 4s on Sphere, 3s on Force Pulse, and 2.5s on Riftwalk. I repeat: 3 seconds on Force Pulse. In the late game team fights where you've got 4v4 and 5v5s going on, you WILL have the requisite 6 abilities cast during that period and with nearly 500 AP, you will be doing 800 AoE damage every 3 seconds.

---------------------------------------------------------------------------

One last thing:
This guide talks a lot about riftwalk spamming, but Riftwalk spamming is not something that benefits from the AP you just spent all your items gaining. Riftwalk gets .4AP on the initial damage and no benefit from extra charges. You're getting, from the 700 AP you claim, an additional 280 damage. Flat. 0 charge rift would cost 100 mana and give 400 damage. Then 200 mana and 520 damage. Then 300 mana and 640 damage. Then 400 mana and 760 damage. 500 mana and 880 damage. 600 mana and 1000 damage. And if you had 0 AP? That would still be 600 mana 720 damage.

You're going from a 1:4 mana to damage ratio and steadily increasing you a 3:5 ratio. Meanwhile, a single Force Pulse (which a full 1AP per AP) from you with that kind of AP would be a whopping 1000+ for 80 mana.

Just saying, I'd much rather be able to spam Force Pulses faster than cast more riftwalks. By the time you've spent over 20 seconds charging your rift, you're just not gaining enough additional benefit.

Which is all well and good, but I would argue that that is a different item setup than a pure AP build.

Yeah, this guide was written originally when riftwalk used to be overpowered (as senate mentioned) nowadays, it's a lot less powerful than it was

but yeah why frozen heart? i would take nashor's tooth over it personally =P

Like I said, at that point it's usually a toss up, but I would take Frozen Heart over Nashor's for the armor if it was a physical-heavy team. When I have 500 AP, 50 more is good but a pittance compared to the benefit from armor. At level 18, I'd have 72 armor, FH increases that to 182, or a difference of 42% DR to 65% DR. Add to that the -25% attack speed aura to your enemies, and simply being in the fight is crippling the damage output of the enemy (once again, assuming a physical heavy team).

By the end of the match, you're pumping out serious damage, but very few of your items have increased your defenses. I find it to be helpful at this stage of the game to fill in that weakness. Your passive takes care of abilities, though, so if you're not fighting a Malphite, Yi, Tyrandamere, etc. Nashor's Tooth is definitely worth picking up over the +armor.

I like your build, my final build I've had success with is Archangel, Rod of Ages,
Nashors Tooth, Hextech Gunblade x 2 for survial, Zhonya's would be nice, but late game I'm more worried about living, and a silence wrecked me with your build it has decent Ap ratios with lifesteal and some spellsteal with nashor's I have the AS to take some people out.


Mainly needed it when there was a garren, I'd riftwalk him 12 times and silence, force pulse, nothing, he's still at 80% hp so I'd force pulse to slow melee him down port away from bladespins..back in after, prolly should have stayed ap with a void staff but it worked

This was a great guide i'm really new at this game and Kassadin was my first buy. This guide actually makes me get some kills. Other guides didnt mention some of the stuff you did. Thank you so much for this guide it helped me so much!