@Meddler: A bonus-gold-to-damage hyper-carry Champion. Would it work?

I've been working hard at making a good, suitable thief Champion for League, and I've got a design I feel works well. But, of course, there's always some nagging doubts in my mind that some parts of the kit might be fundamentally "anti-design".

One major part of this thief Champion's kit is that she gets bonus gold by weaving her abilities and basic attacks onto enemy Champions, and by being involved in Champion kills (in a way similar to Katarina or Jinx). Then, when she gets her ultimate, she gets bonus on-hit proc damage on her basic attacks equal to a small percentage of all that bonus gold. This gives her potentially infinite scaling on it, but requires her to make lots of hit-and-run attacks or to gank a lot to build up a large amount of bonus gold.

Is this idea one that could work in League? Seeing as Ekko has a modified version of Weaver's ultimate (DotA), I'd love to see a Champion who gets a "bonus gold ratio" to add to their damage.

For more details on the thief Champion, check here: http://boards.na.leagueoflegends.com/en/c/skin-champion-concepts/gEIw1dEE-severa-the-princess-of-thieves