a few overall changes i would like to see
not sure if this is the right board but for starters possibly some changes to the death recap like the bar being moved to the top of the screen (most of the time i go to click the shop i open it by accident) and or made smaller it would also be nice to close/minimize it using the esc key or even turned into a smaller permanent button placed around where the current game options and screen settings or near the CS/KDA oh also it would be nice to see some skill info like the duration of stuns/roots/silences and all that instead of a general description of the skill used on you
second Malzahar VU <3
third some changes to the mastery system like letting us add points where we want instead of having to either go all in one or split them in half to get to the next tier. possibly a fourth tree so we can see categories like damage, tanking, utility and i don't know maybe some more that changes the effect of some items, like a mastery that would change healing potions to mana pots (empty flask item which can be changed depending on what mastery you have) or a keystone mastery that would unlock an extra inventory slot i think a fourth tree would allow you arrange some of the current masteries around so people don't have to get masteries they don't want in order to get to the ones they do want. or even a click and drag style system where the masteries are already maxed out and we have maybe like 10 slots or so of our own tree to customize with any of the ones we want
also as an idea to fix warlords bloodlust or whatever it was called, i think one of the main problems with it is its duration and cooldown if the duration lasts longer than its CD then there's no point in giving it a CD at all, i would recommend maybe something like a 30 second cooldown and a 10 second duration not just on the attack speed but the healing as well or just some tweaks to the values ( i haven't used this mastery yet so i'm not sure if the 2 second CD only kicks in after the 4 second duration or what)