They pretty much would just be in stock for back up, in case one of your demons gets curb stomped. Then again... that would take a lot of the suspense and fun out of fighting....

We'll see how it works out, but anyway, yes, they'd be in stock for later use. They can be used for summoning other demons or switching out the demons in the party outside of battle...

I've an idea for this now, I'll post it soon.