I don't care about game moments, like start, core. I only put the items that you should buy in some situations. I do consider Void situational since sometimes I prefer having a Zhonya first. Also most of my games with Xerath I don't reach to get 6 items since I push the game to an early victory.

I prefer Archmage and Spellword than ugly cookies, I guess we have to agree to disagree. 5% AP of 600 is 30 AP. 30 AP equals 23 more damage from your Q. Plus your masteries well used can give you up to a total of 12.5% more damage to your enemy. Then 23 becomes 26 damage can be applied to 5 persons, that's 130 damage in 1 Q.

Cookies makes your early potions to heal 20 health and 10 mana, that's cute, but I already have mana regen and I don't need health since I know when to encounter an enemy and when not to. The only good utility mastery is the one that increases the duration of your buffs, but I rarely get one from my jungler and if I got it from a kill it's just luck.

Also I did not said that Xerath is super safe, I mean that's stupid, he does not have any escape, dohh. Xerath can play safe as long as he knows his enemy and his position, and that does not mean that he is safe. You're the only one here accusing with false testimony.

If you miss your stun, you'll die. If you hit it, you'll make the difference. Let me introduce to you: The Skillshots. By your thinking I shouldn't pick either Lux or Morgana, since if you miss their bindings you'll become an easy target.

When I said that he must be fed to make the difference, as I already said back there, is that since xerath needs to buy chalice to stay in long teamfights, some other midders do not need sustain items, hence they can build straight damage and winning an all in battle making you lose 1v1 or let your team fighting 4vs5.

Seeker's Armguard isn't core item

Void Staff isn't situational item

Exhaust should be mentioned

24/0/6 isn't really optimal since Archmage and Spellsword aren't really good masteries. You could use those points more efficiently by putting them to utility tree

He really doesn't have to be fed to be efficient

Greater Seal of Mana Regeneration aren't really the only choice. Saying that he is super safe is false accusation. He doesn't really have any way to escape champions that can close the gap. Your stun can miss and therefore you can end up dead or at least low health.

His mana needs are up to you, you don't even need Athene's if you choose to play him like an assasin, but in my opinion these runes and masteries will allow to my game style to poke more and harder. Also sometimes you can not trade AAs to proc your passive against champions because you might get very damaged.

When I said useless I meant it about his propose as an APC, he won't be able to do a lot of damage if your teammates starts an unnecessary teamfight, since Xerath's first item is most of the time Chalice (+0 AP) or Athenes (+60 AP), if he does not get kills he won't be able to make the difference against midders that do not need sustain items for their ability bar (energy, mana, fury). For example, if you're playing against Zed and you choose to make Seeker's first, you'll have 35 AP if completed, while with that money Zed can buy a brutalizer and punish in earlyer teamfights.

There's not a single useless champion in the game, but some of them needs to farm or get kills to make the difference. AP midders usually should be looking for damage and not CC, because it does not matter if you have an Alistar support while your midder is tickling the stunned champions.

To be honest, I disagree with your runes and that Xerath is mana hungry. If you utilize your passive you will be fine. Yes, I understand he does have some mana problems, but they are not drastic. I also STRONGLY DISAGREE with that without any kills, Xerath is useless (something like that. He has great cc and poke... Xerath is never useless in my opinion.

Thanks, I'm still trying different kind of masteries, I just placed in this guide the one I use against most of AP mids. Against AD 21/9/0 gives me more confidence about staying alive, but against AP I'm only looking for sustain, such as 1 health and 3 mana from Feast and 3 mana per 5 seconds from Meditation (utility).

Expose weakness kills all those lucky players that stayed alive with 10 hp, not much difference, but for now it's working for me ^^.

I don't always get blue buff from my junglers, and sometimes I just let them have it so they won't be behind in level.

This looks like a decent start! I'm curious, why do you favor mastery points in Butcher , Feast, and Expose Weakness rather than opting for Runic Affinity in the Utility tree?