dark harvest needs changes (not because it's busted but different)

so dark harvest. I don't know what exact role it was supposed to fill, perhaps the edgelord assassins for that extra damage to burst someone down or whatnot, but it doesn't do that right now. it's supposed to encourage going in for kills but why risk doing that when you could just farm stacks off of minions for a few minutes? and why go in at all with this keystone when you could just poke them with a single skill from safety and get the damage off there? my point is it doesn't facilitate any forms of all ins and goes against what I thought riot wanted for the assassin burst pattern in terms of counterplay. so why not do this? instead of a burst of damage give the first hit on an enemy champion a short duration vulnerability so the skills within that time do more damage and you're golden. P.S. I don't play assassin much but when ezreal is taking this keystone you know something is fucked.