This is a raw idea for a Light unique/legendary tower. Beacon of hope.
I am not entirely sure on the mechanics, but the general idea is that the (internal) tower level gets increased through support from other towers.
I have 2 basic concepts. The first is that the tower itself is the carry, the other is that he generates an item that another light tower can equip.
Both versions stop the attacks of all lights towers in range, in exchange the Target Tower gets the levels of all stopped towers added to his level when it comes to calculating the base damage. Maybe even the level dependent buffs(potions, items), but this has to be tested cause it might be too strong.
Also it might be useful to restrict the item to be only usable in the range of the tower.
The base stats as the support tower would be irrelevant (as with Ganesha for example). The carry version really needs a deeper look on the design.
I just wanted to put this out there for discussion.
First off, great idea Kami!
I think I'm favoring both versions at the same time :-D
What about you can build it on top of a light tower only. Then, that tower gets augmented with the level bonus that Beacon of Hope provides. It is still the old tower, it just get's an additional permanent effect.
A bit like mutating creatures in MTGA.