With this build you not only get a bunch of health and can still tank for the team, you also have AP to the point were your ulti destroys anyone's health. Now i know the will of the ancients looks useless but it gives spell vamp to ur ulti so now if you end up getting low pop ur ulti and watch ur health come flying back. Remember even though ur build does not look so tanky if u farm well you can end up with 4k health.