I'd add Carnavons to certain undead waves to make you feel more cornered.
Tower defense missions?
Sorry, I thought putting undead would imply all types of undead, I'll be sure to make the post more clear!
Thanks for your feedback!
Only one question: ^^
Would we still control our knights as well or just place towers?
You would control your knight, I'll be adding something extra to the post now.
I thought Carnavons to be a rather special kind of undead and wasn't sure if they were included. It is something about the reviving totems that make them feel like "real" zombies. I imagine wave after wave of these things would give the tower defense a really nice touch.
Adding ideas:
I think if was set up like an arena and you could choose to quit after a set of waves or to take the next set with an increasing amount of rewards, it would make a nice set-up for energy turrets.
Make them less useless and those 5 energy seem a better option than using a spark of life or paying 200+ energy.
Edit: Some enemies should prioritize the target rather than attacking you and letting them reach and damage the target could activate some sort of haze bomb making you suffer a status condition according to the theme of the level.
Some sort of endless arena (or very large arena) would be a lot of fun. As long as there's a large box reward afterwards it would be a lot of fun.
I can see a swarm related one of these happening as well.