Neu Midgard: The Second Age of Steam
The year is 0200 AC. 200 years ago, the war between the Midgard Federation and the Colonist Republic of Asgard, known as Gotterdammerung, ultimately led to Ragnarok, the fall of Asgard's space colonies to Midgard's surface, causing a planet-wide ice age, destroying the Federation and nearly wiping out all life on the planet. Through the tenacity of the survivors and the efforts of scientists, druids and priests, the frigid planet was revived though the enormous changes brought about meant that Midgard was never truly the same.
With the infrastructure that powered the Cosmic Era technologies destroyed by Gotterdammerung and Ragnarok, the quest to rediscover the lost technology led to the rise of a new profession, the Geier. Just like their namesake, the geiers scavenge old cities and military bases for cosmic era technology for use and reverse engineering.
As time passed and power reserves ran out, the people shifted from the dying Cosmic Era facilities to more primitive but simpler and reliable technologies as they work on rediscovering the manufacturing process. Thanks the the technologies they uncovered along with studies of historical and technical texts, they've managed to work their way up to prana-enhanced steam power and gunpowder with unprecedented speed as opposed to the natural progression prior to the Cosmic Era and shows no signs of stopping. Unlike the Age of Steam prior to the Cosmic Era, the Second Age of Steam revived the concept of Walker Machines: enormous mechanical piloted constructs that forever changed the field of battle and once thought to be the key feature of Cosmic Era warfare.