How would people feel about Devourer getting Bloodrazor's old passive?

That is, in place of the flat magic damage that scales off kills. This seems like a smoother way to allow its damage to scale through the game without bothersome edge cases and the like. Maybe not the 4% value precisely, but that general idea. %Max HP damage in place of farming.

For those that don't recall, Bloodrazor was an item that did 4% of the target's max HP in magic damage OnHit. It was primarily a jungle-control item, but it worked decently on champions as well.