The fierce warriors that hailed from the northern isle of Ismenn do not believe in religion the same way as their softer southern brothers. They believe that the gods are as giants to us, and care not about our actions or beliefs.
They do believe that a few of these giants gave gifts to the Ismenni as their chosen people, and should be revered for that. But praying to them would do no more good than begging a heavy snow not to come through your roof.
The most revered Jotunn include Uldir who gave the Ismenni steel, Ocelan who gave them knowledge of the stars, Bort who showed them how to till and ferment grain and Cerdan who gave them the skills to build ships. But they are all children beside the earth-dragon (which has no name, or simply ‘dragon’) from which all creation stems.
They also believe in Surtri ‘the black one’ who will burn the world at the end of days. It is largely believed by the Ismenni that Baor is truly Surtri in disguise.