Current Nauilus Shield changes are actually a nerf early game when you consider runes and masteries.

At first glance the change seems like a slight buff, because it scales now with total health, the shield at level 1 is 105 and get's stronger with levels, without buying items.

However, runes and masteries are counted as bonus, so live Nautilus can get 29 extra shield from them, while the new shield would get only 15.

So A Nautilus that is build that way (which one would be not?) actually looses 10 shield at level 1.

It get's even worse if you up rank the shield: At level 3, shield rank 2 it goes from 179 to 157 (21 lost) At level 5, shield rank 3 it goes from 229 to 202 (25 lost)

At level 3, shield rank 1 it goes from 129 to 129 (0 change) At level 5, shield rank 1 it goes from 129 to 135 (6 gained) If you don't rank the shield though, it gets better from here.

But if you do rank shield or buy any health items it's worse until you reach level 10, shield rank 4.

If you slightly raised his low rank scaling to 10/12/13/15/17 % max health instead. It would at least keep his early shield the same.