Taking the various bizarre assumptions of D&D absolutely literally and trying to devise logical explanations for them is something many of us might have done from time to time. This effort may well reward reading with a few novel campaign ideas.
Assignment of Loki to Lawful Evil and Tyr to Chaotic Evil seems .. unorthodox.
The OGL section 15 for each product I've seen in this series is incorrect. This is important, apart from anything else, because it fails to give due credit to the designers for their hard work that the author is using free of charge.
[4 of 5 Stars!]
I'm using a standard version of the OGL. I downloaded it from WotC, if I remember correctly. Please let me know what I missed in section 15 (email me at email@example.com) and I'll try to correct it.
I realize Loki is usually considered Chaotic, but you can't be tricksy without rules to circumvent! If you cheat Tyr on a bargain, he'll just get mad, crush your skull, and take his stuff back (and your stuff too). Loki expects you to live up to your part of the deal, even when it's bad, because it's a deal (and Loki will feel bound to his promises, too, even when they go against him). To me that seems more lawful.
Thanks for the review!