A summery of all the changes incoming with the Patch 3.7 update:
Champions being changed included Akali, Caitlyn, Cassiopeia, Diana, Elise, Jarvan IV, Karma, Miss Fortune, Mordekaiser, Nami, Nunu, Quinn, Rammus, Rumble, Syndra, Twisted Fate, Udyr, Varus, Warwick, Zac, Zed, and Zyra.
Items getting changed include Mana Manipulator, Mikael’s Crucible, and Shard of True Ice.
Custom Item Sets and Loss of Control Bars are being integrated within the game. You can build your own custom item sets and set them to a specific map(s) and can be found under the summoner’s profile to create the sets, and under the Recommended tab to use within the game. These item sets are tied to the computer and not the server, so if you play League of Legends on multiple computers, you’ll have to create duplicate item sets on each computer. Additionally, Loss of Control bars will show you the duration in which your champion is afflicted by some status effect (i.e. Silence, Taunt, Slow, etc.).
You can read the full patch notes here!