User blog comment:Nearthel/Kraig, the Beast Master/@comment-24420226-20151102181829/@comment-24420226-20151102215637

@PrimusMobileVzla It's not the presence of an AP ratio that seems odd. Its the fact that the physical damage portion scales only with AP, and the magic damage portion scales only with AD. This means that the physical damage portion becomes less relevant without buying AP (typically you don't on a marksman) and the magic damage portion becomes less relevant without buying magic penetration (also not a stat marksman invest in).

To be honest I'm not quite sure why they are removing the AP from sheen. The combine cost of Trinity Force is only 78 gold, so you can often just purchase the 2 components you use the most stats from (Zeal and Phage in this case) and then just combine those two to 'avoid' purchasing unwanted stats. Honestly, the unused AP was less of an issue than the unused mana when buying it on manaless champions. It feels like a mean kick in the shins to Jax and Irelia, who had marginally useful AP ratios on the utility portions of their kits.