Welcome to patch 4.18. While we don't have a lot of balance changes this patch, 4.18 is the launch date of one of our largest champion updates to date: Sion, the Undead Juggernaut. Be sure to check out his champion reveal page here, or just try him out in-game when he launches! But please, for the sake of you and your teammates' sanity, maybe play a few normal games with him before you queue up for ranked. I get the feeling many of you won't listen, but at least I've had my say.
Also of note within 4.18 is a whole pile of bugfixes for Azir (sorry!), a GANGPLANK BUFF!?, the removal of Pando Media Booster, a Smart Ping volume slider (look at this new audio technology we can implement!), and phase 2 of our mass champion texture rebalance! You can think of this patch as more of a small maintenance update as we look forward to the World Championships in Korea and the future of competitive League of Legends. Definitely some bigger things to come in the future, so stay tuned!
P.S. Same deal this patch about there being larger than usual downloads. We're shipping pieces of the updated Summoner's Rift as we finish them but, once again, they won't be available to play!"