I haven’t been here in years so i have a question about the delta sprites people make. Are they meant to be implemented in Insurgence only, or can i use some of these sprites if i get permission from the sprite’s creator ? I dont know if this is the right spot to ask this question, so my bad if it’s not 
If they’re sprites on Holon University you can 100% DM the creator to ask if you can use them in your fangame. You might not have a whole lot of luck on the forums though since, much like you, most people don’t go on the forums all too often. You’ll likely have more luck finding their discord account and DMing them there.