I watched some DOS2 videos in the past that showed spell crafting (taking two different spells and combining them to create an entirely new spell). I understand that this new system hasn't yet been introduced, but after playing Early Access and seeing the spells that are available it makes me think about potential combinations.https://www.youtube.com/watch?v=__wzUv582lI
(old video but it shows what I'm talking about)
Here's one that I thought would be clever;
Filthy / Fireblood - Enemies in target area will bleed fire when hit. Creates a small fire surface beneath each target.
Contamination - Deals X-Y damage and sets Poisoned to enemies around you. Turns water, blood and surfaces and clouds into poison!
Combine those two to maybe create Poisonblood -- which would be really funny with Comeback Kid and Zombie.
Anyways, have fun, and share your ideas about other combinations with the existing spells that you think would be interesting.