Okay so... let's talk about Xerath. He has 4 skillshots which you HAVE to hit if you want to do some damage, right? I agree his power is in the range BUT lately there are many champions that can start jumping around to dodge your spells and then literally 1 shot you (kayn, kha'zix, zoe, yasuo, leblanc, katarina and many many more) and since Xerath lacks of any mobility there is no counter play to that. I see Riotgames wants to keep champions up to date but i belive that Xerath is outdated. I also like to mention that he is pretty much useless against tanky champions, a champion with 3k hp and 150 magic resist can tank his whole kit and his health bar will not even be halved so unless if you play against 4-5 squishies Xerath is not a good pick for the game. To bring him back into the game you don't have to rework him like you do to other champions, but just to buff a bit his mid/late game damage and give him some true damage passive (let's say you can stack something up to 8 times each time you hit a skill and it gives you 100 bonus true damage on your next skill each time you stack it but it's for let's say 3 seconds so you can hit a combo with a maximum 8 strikes - E, W, Q, R at max stage 5 shots) because it's really unfair when you hit your full combo and don't kill anyone (which requires some good skills btw) and then he just jumps out of the nowhere, distance as huge as your Q's range and hits you for 1000 damage Q. (let's say kha'zix just for example) You can also increase his cooldowns with a few seconds so he can't spam spells too often because with that changes that'd be too op if he just spams spells each 3-6 seconds.