Starting bit late, and with very limited time for actual coding, but at least have some idea :)

Theme was hard to tackle. I rejected obvious 'summonings' like monsters, cultists and stuff (fun, but probably will be quite common). Than I thought about some IRL summonings. One of good ideas was to make a game about nurses night shift in a hospital, summoned by patients, struggling to be everywhere and keep track of oneself tiredness and sleepiness. BUT it would be too time consuming :/

So, as usual with this 'make/draw/figure out something from a prompt', as a non-native english speaker, I went to Urban Dictionary for inspiration! And I found something fun.. although, I keep literal meaning, not the one from UD ;P