Welcome to my guide to Xerath, The Magus Ascendant
Xerath is a range mage who excels at bombarding enemies from a far distance, As well as poking on enemy champions before the battle begins. In this guide i would talk about the various techniques to fully utilize Xerath's range to his best advantage, giving you incredible amount kills and lots of fun which comes with it.

For runes, i take...
Greater Mark of Magic Penetration
Greater Seal of Scaling Ability Power
Greater Glyph of Scaling Ability Power
Greater Quintessence of Ability Power.

This setup gives me the best damage output during the lane phase, and allow me to secure more kills.

Reason why i don't take ..
Greater Seal of Replenishment/ Greater Seal of Scaling Mana Regeneration - Mana is more than enough just with Tear of the Goddess
Greater Glyph of Cooldown Reduction - Cooldowns on skills are personally short enough as it is.
Greater Glyph of Ability Power - Well, although this would give you a earlier AP dominance, However it falls flat after the 10 minute marks, thus i prefer using Greater Glyph of Scaling Ability Power

For items, i start out with a Meki Pendant, Health Potion Is optional, if you are confident in staying in the lane till at least 605 gold, then skip the health potion and head straight to your lane.

[Laning]
During the early phase, you would want to concentrate on last hitting minions, only do harassment's if it means you will get more creep kills. When you hit 605 gold, it is time for you to Blue pill back home, get Tear of the Goddess and teleport back to your lane.

When laning, always check on how the other lanes are doing, if there's a enemy champion with low health hugging tower, let your ally give you vision of them and you can easily pick up the kill with Locus of Power and your Ultimate Arcane Barrage.

If you are doing well, get a Needlessly Large Rod, Else pick up a Doran's Ring or 2, But remember, this would mean your core build would be delayed much more, so only do this as a last resort.

Here's a List of the Core items you would end up with at the end of everything.

With all this items purchased, you should have about 714 AP as well as 64% Magic Penetration when Locus of Power is activated. A Deadly Combination!