I've recently came up with an idea that well, let's say it, is a bit insane. But let's start with it.
Exploitable laptop - tower card
physical parameters not specified (can be the same as Ganesha).
A laptop equipped with the latest hardware components. On every round, there's a X% chance, where X depends on mutable tower parameters, that the most experienced tower on the map takes the lead of the laptop (so that X depends on the most experienced tower in addition of the laptop's).
When this happens, your tower becomes an hacker and exploits your running Mazebert application, granting the player some "illegal" bonus content. The bonus provided can be anything, not only towers, potions and so on. Since this content is illegal, all this can also include multiple "single" items/towers (such as a further bolefald satellite or mummy bandages).
As stated before, the content can be "everything" as long as the hacking concept is involved. By everything, I mean that bonus can be lot of money as well as advancing n levels (just few examples).
Since you get lot of privileges from this tower, once in a while (this is the part I like the most) the police finds out your illegal activity, meaning that you'll have to face the police with the bonuses you've earned. In this case, the police can be an overpowered creep (or an additional Horseman, overpowered as well).
Well then. What do you think about it?
+1 from me!
EDIT: Although I think this will be really, really challenging to implement/balance.
But the idea is awesome!
Yes, the implementation would be pretty tough, but it's a card every player would please to have in his map even during
the high rounds (200+) when the game begins to turn into something utterly different (countless money bins, high-overpowered main tower and a very few variety of tower cards).
My aim is just giving some ideas for creating new cards to use in 200+ rounds. That's all!