only needed 2 items (testing out new mythics). I can confirm that Radiant is best for my Illaoi, but I will explore all new mythics! Currently finished with this and Jak'Sho. :
Illaoi Top Build, Runes, Counters (Patch 13.04) - OP.GG - League of Legends
This Illaoi build UNSTOPPABLE. (First Strike Illaoi?!?!) - YouTube