User blog comment:Makbloo/Grolk Kar, The Great Wyrm, Kog'Maw's Daddy/@comment-5250437-20121118070114/@comment-5127158-20121118100456

Well as stated before you have to farm 500 minions to reach maximum armor and magic resist from your innate and the bonus AD and AP from W's passive is taken from the Armor and MR gained from the innate. So if you have farmed lets say 200 minions you gain: 40 Armor and 40 MR, which also give you 12 AD and 8 AP. The bonus Armor and MR are good but they work similarly to Nasus's Q and Sion's ablity increasing his health (i think its his E), since they require a lot of farming to give usefull bonuses. The bonus AD and AP are almost negligible. In fact I'm cnsidering removing them.

He becomes tanky but as tanky as any tank would.