League of Legends (LoL) Question: Null Magic Mantle start?

I think it may be viable against ap tops that don't auto-attack harass like Rumble. Beyond that, Doran's Shield is better.

Imo outclassed by every start because:
Null-Magic Mantle gives no HP or any other stat than Magic resistance which is already 30
With runes it is even more than 30
Early game harassment is pretty much only autoattacks
Forces you to buy something from it pretty early - otherwise it just takes one place
Doran's Shield for example, gives HP, armor, passive - all of them combined it makes pretty darn good defensive item
If you don't have HP to back up the MR it's pretty useless.