What if we reversed the active on Ohmwrecker?
Where it buffed allied turrets instead of disabling enemy turrets? That way supports could build the item against a dive heavy comp to stop some dives from happening. I'm thinking:
Active: Ohmwrecker
Buffs a selected allied turret for 5 seconds. During this time, the turret and all allied champions under the turret take X% reduced damage from all sources.