The new 9.21 patch is the first to arrive after the 10th anniversary celebrations. Although there are no changes that can be considered as a complete renewal, quite effective changes have been provided. There wasn't a lot of time devoted to this patch as Riot Games spends a lot of time and effort on Rise of the Elements updates. However, some additional settings for the update on the champions that have received major changes in patch 9.20 have been included in this patch and of course are in other works.
Also, new skins are coming to the valley on October 24th ! Here are these costumes;
Witch Miss Fortune and Presitj series, Annieemo, Count Kassadin and the Witch's Cauldron Blitzcrank
Patch 9.21 Highlights