[@Hammerman]

I'm interested if your still looking. 

Would probably be most interested in a Dark Twist to number 1: Namely a Hero summoning gone very wrong. 

Basically instead of summoning a hero the summoner calls forth a Demonic Prince that by background happened to be stuck in between worlds. 

More specifically, with chance of other twists is that the war that broke out between demon and man, started in the demonic realm as a war of accession. 

Two siblings was suddenly left with a empty Throne when their Demonic father 'The True Devil' kicked the bucket throwing the demonic realm Into chaos... Well more so than usual. 

Demons fought demons and tried to get the Throne. I. The middle of this, for comic effects. The sister Betrayed the brother and banished him making him stuck between worlds while she took the Throne. 

Now she sits upon the Throne and the war which plague the human realm started when rifts opened up. 

Could be long after the actual banishment.