Randomizer for finisher effect MTX

We have several finisher effects now as MTX, both for rare and unique monsters. For portals, we have the option to use a random variation of portal MTX for each portal. It'd be cool if we could also extend that for finishers. Use a random finisher MTX effect when a rare/unique monster is killed. That way I don't have to select one, we can just own a bunch and have it cycle through them for each rare or unique killed.