I chose these runes on illaoi for a few different reasons. Conquerer allows you to gain more health as if you know how to stack it correctly, this can be very broken on illaoi. Next, we have triumph for more lifesteal. After that I went ahead and chose tenacity as being stunned as illaoi can ruin her. The quicker you can get a w off, the better. Finnaly, I went with last Stand. Now, here, you could also go coup de grace, but I've found last stand to be better for teamfights or being ganked. For secondary runes, there are a few things you could do here. The main rune path I chose to run though, is domination. For the first rune, you could do one of two things, either taste of blood, or sudden impact. I personally prefer to run sudden impact for the increased damage, but if you find it harder to survive, taste of blood is also a viable option. For the second rune here, there is no better option than to run ravenous hunter. Even though it may not be a large amount of healing, it is still a very noticeable amount.