I like the build, though I would get a banshee's instead of Force of Nature, since you don't have a lot of health to regen, and the spellshield is amazing on Kassadin. I would also probably get it a little bit earlier, especially if you're going to be up in people's faces trying to melee. As you have your build right now, most competent players will obliterate you after your silence is over. Banshee's also lets you use something like flash, which I prefer to cleanse because it can be used both offensively and defensively, or simply for extra mobility if your Riftwalk just isn't cutting it. For armor the Frozen Heart is much better than thornmail, with a whole lot of armor, reducing their attack speed, mana for more teleports and ap from your archangel's, and it will let you get some spell penetration or tenacity boots instead of cooldown reduction. Really Kassadin is too squishy to effectively use thornmail.
Masteries should be reworked to get you far enough into the offense tree to get the magic penetration mastery in the third row down. It's one of the most useful masteries out there for Kassadin. Kassadin doesn't really need the small boost to his movement speed since his movement is mostly affected by his ultimate, and not his actual move speed. The good hands mastery is something you generally don't want on any character, especially one with as many escape paths as Kassadin.
The magic penetration marks are infinitely better than the ability power marks and will give you more damage in any situation. For your build you don't really need mana regeneration, since you melee with netherblade, so the rest are ok.

After reading the whole guide though, it's good. You explain the abilities well, provide reasoning for items, and I really liked where you explained the different tactics that you can pull off with Kassadin. My only concern is that most high level players will counter this very easily. Not being level 30 yourself, you play against other low level players. Your stuff like "Hit and Run" doesn't always work against players who are level 30, and someone like Ashe or Caitlyn will do a massive portion of your health as you move back to your turret. Most level 30 players will also see a teleport and move far enough away that you can't just Riftwalk onto them for massive damage either.

This seems like a fun build, but I have doubts about it working against level 30 players. I'm going to give it a +1 for the thought and effort put into it, and the in depth explanations.

Nice in depth guide, just what I was looking for. I've been playing Kassadin awhile and was intrigued with the AD build back when his nether blades still granted AP. After they changed it to give bonus magic damage on hit, I had been mulling around the idea of somehow trying to capitalize on that while still keeping a fair bit of his burst. This guide gives me a good place to start :)

Thanks for the comment!

CDR Boots: I've had great results with these. 15% off on the already low cooldowns means your burst is up more often. Couple that with the 25% from Nashor's Tooth and you are at the CDR cap. Riftwalk is on a 2.4s cooldown, meaning your hit and runs are much quicker. If something goes wrong and you have no CDR, you have to stand around for 4s while your Riftwalk cools down. Here you can pop Cleanse in an emergency and get out before you drop.

Lich Bane Early: Not necessarily. At level 18 his Runes give around 85AP, added to the 55AP from Nashor's Tooth and the 80AP from the Lich Bane. It's not the highest AP, but immediately after getting the Lich Bane you're going for an Archangel's Staff which sends your AP through the roof. Since you already are going to have a Tear of the Goddess the Archangel's Staff is very cheap by that point in comparison to the rest of the items.

Nashor's Wasted: I will slightly cede you this point. However, your passive Nether Blade starts to actually show when you're hitting at 1.3 attack speed, and when activated you get a decent damage boost. In my previous builds I would get a Frozen Heart in lieu of a Nashor's Tooth but I felt the Nashor's Tooth contributed better. And while the Lich Bane doesn't proc on every skill use, it does proc every 2 seconds which is plenty fast enough for chasing down enemies and popping into fights. I jump in, burst and hit with a Lich Bane, then jump out and circle around for another go.

No Tankiness: I'm working on a revision to address this but like I said in the items section, the 6th item slot is empty. I put the Rylai's Crystal Scepter in there for the build list because that's generally what I take, but for all intents and purposes you could take a Warmog's Armor or Thornmail or Zhonya's Hourglass or Force of Nature as the enemy team composition warrants.

Wall of Text: I know ;) I'm actually revising it right now to clean it up a bit and add in tooltips for item and ability references. Hopefully it looks a bit better once I finish it up.

Think Through the Strategy: This isn't a build I just came up with; I main Kassadin and this is the build I primarily use. It does work very well. Most of the time I hit double digit kills and stay in single digit deaths. I'll post a picture of my match history when I get a chance and add it to the end of the guide.

Again thanks for the comment!

Up until boots of speed is fine. CDR boots? Questionable. Nashor's Tooth? Not good on Kassadin at all unless you're doing some gimmick build with his new Nether Blade, which you're clearly not. This build gets Lich Bane early, before you even have much AP, which is generally a pretty bad idea. The attack speed on Nashor's is pretty much wasted, and it seems like you have to stay close to opponents since this is a less bursty build, yet it has no tankiness to allow him to do this. Against, say, an Annie in midgame, you would start off with a silence and such, but before you get her to 1/3 HP even, she would just obliterate you with her combo, leaving you dead.

Very confusing.

Don't let this discourage you, though! You had a big old brick of text, which is always welcomed in guides, just maybe try to think through your strategy a bit better and make sure everything works together, not just "oh this seems like it could work". This build would be great if Lich Bane proc'd on every skill cast, but it doesn't, and it makes Kass worse in mid game, but later into the mid game and into the end game, he can probably do more damage than with other builds but again, he has no survivability at all and he'll still drop like a rock.

Thank you for your comment and vote! Glad you enjoyed the guide. As my first one here on Mobafire I'm not sure how to add the item and ability tooltips but it's on my list of things to do - I've checked out some other guides and I'll be going through and cleaning up the formatting for the next revision.

comment4vote

Very well written guide, I used to main Kass but havent played him in ages.
Your guide explains everything very good!

Hmm, I should've read patch notes.. Didn't know he got his W buffed..

Anyway, +1(0)

*edit*

You might want to edit in some skill/item icons and text colours, they will make your guide look less like a wall of text and make it more appealing to read ;)