A buff to make Ohmwrecker useful. Hear me out, Riot.
Meddler posted on one of my threads regarding to Ohmwrecker explaining and deciding to rework the item once more after this season. Here is my suggestion.
I was looking at some of the items that was featured in the Black Market Brawler event. There's an item called Rite of Ruin.
Rite of Ruin: 100 ability power 100 mana regen. 20% cdr Unique passive: Razing - Gain charges upon moving or killing enemies (200 charges max). Attacking a structure expends 50 charges to deal 100 (+15% AP) bonus true damage.
Instead of the item scaling with AP, make it scale with tank stats such as health, magic resist and/or armor.
Or maybe turn Ohmwrecker back into and AP item like it was and apply the passive from Rite of Ruins.
It fits with the sieging theme of the item and gives it more use. That way you can siege by attacking the turret and if a teamfight occurs around the turret, you can use the active.
and I would love to buy it for my tanks back in season 2, but even then I felt that it was redundant since I would eater buy it by late game when the turrets are gone, or rush it when I could have use that gold for other useful stuff (like MR). then to top it off, 
has the same passive from 
but allows you to drop a voidling maker that can be used offensively to destroy a tower or defensively by setting it in a lane that lost its inhibitor.
(600) + 400 = 