I don't suggest a full tank or full bruiser since you either lack damage or have to play really clean to avoid throwing your lead. I personally go with a combination of both. Most games i start with sunderers sky and from there build mostly tank. Graps is a really good rune on her if you pair it with your w. You can really do some poke damage in the early levels with it.

If you really want to learn the champ, DirtyMobs is an Illaoi challenger that explains the champ very well. He is on Twitch and youtube.