Bring back fortify, add it ohmwrecker.
Way back in the day there used to be a summoner spell I was very fond of called fortify. It was a great support spell to save towers and occasionally kill people diving under them.
Now as a tanky support I love the ohmwrecker item. It is great item, BUT I feel like changes to zzrot have put zzrot miles ahead as an item.
What I propose is to allow ohmwrecker to disable enemy towers like it current does, or fortify your own towers (and grant them damage immunity like the old fort spell used to) depending on which tower you are next to.
Perhaps it could even give you the gold for kills during the duration.
I just like the idea of a counter to the zzrot and this could be one.