Steam age: I am the God of reverse contract

If, I mean if while appreciating the moon, you are brought to the era of steam and fog by the six pointed star array that suddenly appears at your feet. Moreover, a girl with a pious and awed face is praying to you seriously and asking you to defeat the extraordinary creature in front of you and promised to sacrifice everything to you so, what would you do I really can't fight monsters wait, what kind of mental pollution? I am the master of God also known as "I, who was contracted by the gods, was immune to the invasion of the unknown"