User blog comment:Willbachbakal/(Champion Rework) Viktor, the Machine Herald/@comment-25055899-20140630104051/@comment-1330314-20140701101622

I was thinking that an enchantment-type system would work better for the Cores here, with the difference from boots being that switching vision trinkets would still be free. A -style evolution system would make Vik go back to being a generalist, which is the exact opposite of what I want him to be.

While the stats on the Cores are massive, I tried to account for that by removing a huge amount of stats from Viktor himself: without his Core, he would be severely underpowered, to the point where he'd need an extra item just to compete with his opponents (which is sort of the point here). The advantage to giving him such an item in his trinket slot is that it allows him to have as much freedom to build as any other champion, with an extra layer of choice thanks to his three Cores.