or ole ram in ya balls, he scales off armor
To the OP: No items are needed for Damage or HP anymore as both can be got together that will scale infinately as the game goes on. SO full tank builds are simply expected. It was Riots Idea to make Grasp, overgrowth and Gathering storm all avaiable to one champion. Personally on a champs like
They are more powerful than others.
For example Vlad gains ap for hp and hp for ap
grasp procs he gains +1ap and +2 hp,
Overgrowth = 40 minions he gains +1% max hp which transfers into AP
Gathering storm = Ap every 10 mins
Granted nasus gains the most outta grasp as far as procs. the rest are just to slow or ranged and slow.
Gathering of the storm allows Cho'gath to build pure tank
I might trade grasp for AfterShock bc Q procs it and the bonus mr and armor help.
though I put
in my build for top. If I'm bally I'll even put in 
Reasoning?
20%hp scaleing scales with runes and cho himself.
Nashor's bc you need more damage than R with more aa speed and damage you can actually fight.
Abysmal is staple because I get a nashor's and cinder item reguardless
and abysmal amps their damage by 10% while giving me more hp and mr