Corki's passive is disadvantageous and useless at all stages of the game
The auto attack split between magical and physical damage makes corki disadvantageous at all stages of the game, since at levels 1-6 it is bad, because the total auto attack damage is reduced by both MR and armor. Before the rework the passive was 100% physical and 10% true damage, and in laning phase we could trade auto for auto with the enemy adc and come out on top. In this patch, we would lose every trade, since level 1 vayne or any other classic adc auto attack damage will deal more than Corki's level 1 auto attack damage.
Later on, bruisers and tanks get their
items, countering the E mr shred and the
boots. We want to build penetration, but our best option is void staff, which in team fights only applies to ~70% of the damage, and the AP doesn't help much since corki's AP ratios are low.
This is so mind-boggling if you think about it, because one could build adc ahri or adc twisted fate for example, build AD items along with a last whisper item, and actually deal more damage to tanks than Corki.
> HEXTECH SHRAPNEL SHELLS: Corki's basic attacks deal 110% of his attack damage evenly split between physical and magic damage. Life steal will apply to both damage types. > The 55-55 modifiers interact with critical strikes and Runaan's Hurricane item.png Runaan's Hurricane's Wind's Fury while other 'bonus damage' effects are applied as normal.
The whole point of the rework is that corki's auto attack bonus damage scales with sheen and critical strike effects. as off patch 6.7(REMOVED: 10% increased damage), there is no point of having split damage, and it is actually better to have 100% physical damage.
Tl;Dr : It is better for Corki to have 100% physical damage than 50% physical/50% magical damage, because it is crucial for levels 1-6 which determines bot lane winners, and also allows Corki to use the AD itemization(Black cleaver, Last whisper, Ghostblade, etc).
This bastardization of one of the most solid adc must be handled by riot asap.
. Considering this fact, corki is the only adc which his auto attack damage is reduced by the locket aura.