This guide will teach you everything that you will need to know for playing Xerath support and how to really help out your team. An unsung hero, Xerath makes a fantastic support if played correctly and has great potential to transform into a late game powerhouse and carry. As I have experienced, your team will not appreciate you and at first will think you are trolling but will shortly change and love your supporting ability

Remember as Xerath you have outstanding range! Utilize your ult and poke to secure kills only if you can assume that your carry will not be able to do the job. You can also use your ult to hit distant champions (if not near the fight) to get yourself some extra assists. But DO NOT TRY TO TAKE THE KILLS WITH IT!!! If a champion is near death in a fight and you have your ult activated, try to focus another champion if it is likely that the lower health champion will be killed.

Xerath is not a traditional or often played support so there will definitely be a skill barrier when using him as a support. All of his abilities are skill shots that will take time getting used to and take some skill in anticipating the movement of enemy champions but you will catch on soon. Once you are used to this and are able to master it, you will see just how useful and powerful Xerath is in the role of support.

Your main focus is to poke down the enemy ADC as much as you can. This will grant you gold and give your lane and Jungler better opportunities to secure kills during ganks or just in general. Remember to focus your poke on the ADC as much as possible and try to sieze opportunities where you can hit both champions at once to conserve mana and maximize gold income. Continuously poking down the enemy ADC will also do a good job of keeping them off farm (since you can hit them at such a far range) and force them to back much more frequently causing them to also lose XP as well as gold. Make sure to utilize Xerath's passive (restoring mana on basic attacks once every 12 seconds, double against Champions) by attacking enemy champions with basic attacks whenever your passive is available and you have the opportunity. If you are not able to attack a champion, restore mana by attacking minions but try to attack the minions with more health to avoid stealing farm from your carry. Just like any support, make sure you ward as much as possible and try not to take kills/farm from your carry (farm is bound to be stolen because minions will become collateral damage in the act of poking).

Use your range and AOE damage in team fights to really lower enemy champions health and to stay our of danger yourself. Use skill shot stun to save retreating allies from approaching champions followed up by a concentrated W to slow them down. Use your kite and range to your and your team's advantage.

Pros:
-Great poke in lane
-Good sustain with mana and potentially health
-Range allows you to keep distance from danger and secure kills that ADC cannot
-Fantastic AOE damage and even better kiting ability
-Ability sequence is very helpful for disengage on approaching champs and saving the ADC
Cons:
-Not very tanky and is very easily brought down when champions get too close
-High damage and range makes it easy to accidentally take kills from your ADC
-Poke will take farm from ADC and can push the lane in excess