Rumble's Current Problems

Rumble is one of my favorite champs. I played him to great effect in S5, and I absolutely love his Super Galaxy skin (it's my favorite in the entire game). However, the changes in preseason have been unkind to him. Rumble's win rate now sits at around 46% across all ELOs, and at the same number in mine (silver). Lest it be thought that he does better in the higher skill brackets, champion.gg reveals that at platinum and above, his win rate is an even more abysmal 44.5%; this places him at 51st of the 55 common top laners tracked by that website.

I'm curious to hear others' thoughts about what (if anything) should be done to help him out.

Sadly, I've pretty much stopped playing Rumble due to the giant hit he took. Even in games in which I snowball, I still seem to be only marginally useful, rather than the wrecking ball I was in season five, and my mid-game power spike seems to be substantially smaller than in season five. As I see it, one issue is that the cost increases on AP items hurt him badly. Three of the items in his core kit (Zhonya's, Liandry's, and Rylai's) are now more expensive by a whopping 900 gold. Of particular issue is the enormous cost increase to Zhonya's, an item basically essential to his survival in teamfights. The increase in cost to Haunting Guise (200g) delays his mid-game power spike, thereby shortening his window of peak efficiency. The slight buff to Seeker's Armguard was also detrimental, of course, as it both reduced that item's efficiency in protecting against AD top-lane opponents and weakened the build path to Zhonya's (a big deal, considering the now-giant disparity in cost between the two).

Rumble pretty much needs Zhonya's and Liandry's, at least, in order to be a viable teamfighter (and, to a lesser extent, a viable duelist), and most other champs therefore seem to now be effective in teamfights well before he is. Too, the fact that he's a below-average CSer (dreadful autoattack animation, damage nerf to minions on his Q) makes these cost increases hurt him more than they do most other AP champs; the average AP champ farms relatively well, and therefore can make up the cost increases with greater ease. If Riot hadn't nerfed his ultimate (late in S5), these changes may not have hurt quite as much, because it's a still game-changing ability. But as Rumble doesn't really have space for CDR, his ult is much less of a factor than it once was at the same time as being relatively much more important to him now.

Furthermore, Rumble does not work particularly well with the new keystones. DFT gels with his DoT, sure, but it doesn't seem to apply as well as it does to other champs; more, it's almost objectively weaker than TLD and has been for some time. This seems to be a lesser issue than the item cost increases, however.

My guess is that there are other reasons that I'm simply unaware of. Whatever the case, I'm curious as to what others think about his present state, as well as (if applicable) what might be done to fix it.