User blog comment:Willbachbakal/(Item Concept) A New Kind of Crit/@comment-1920550-20150704033147/@comment-1920550-20150704052951

I'd make a case about the Shiv/Pillager combo being built for AD spell based mid-game carries that don't build Trinity Force like Graves, Lucian, Miss Fortune, etc as a way to give them that mid game instant burst power. The IE/PD combo on the other hand would work better on more on slower lategame scalers like Ashe, Vayne, Twitch, etc.

Since you did alter the crit interaction to allow spells to count to the 3 mark system, these items would benefit burst-based carries and it would break the Infinity Edge paradigm of being core in 90% of all marksmen by giving them instead an item with more immediate power to snowball off...naturally with the trade-off of having a weaker lategame than the IE/PD users.