How about a name like "Asalaw" (The Law of the Aesir)?
If you want to forge a powerful Germanic empire, which retains it's own tradtitions, it wouldn't hurt to take whatever liberties you need with the Germanic tribes, since little about their internal politics is recorded. The TL I'm writing at the moment is about the early rise of the Suebi to level of Ancient Rome.
Maybe you could do something with the Gothic Kingdoms of Eastern Europe before the arrival of the Huns? Or, a tribal chieftain whom once served in the Roman Auxilia, comes home and puts his dreams of supreme power into action? When it comes to pre-literate cultures, one has much more room for creativity than you'd have with one which has extensive historical records.