What other resource do you want to use to cast abilities apart from energy?

So I was thinking of Hildryn and Lavos when it comes to casting abilities and how they are quite revolutionary on DE's part. I personally wouldn't use either of them if it weren't for their ability resources.

We now have energy casting, shield casting, and cooldowns. What kind of ability resource casting do you want?

I could think of health casting like Inaros's scarab shell but that might become a problem for high-level gameplay if you are not careful.