Soulless: Twisted hell
A crumbling empire decides to take a leap of faith and summon a portal to another world, hoping its resources would turn the tide in its favor. The portal is summoned, but it doesn't lead where it was supposed to. Instead, it leads to a new, bizarre kind of frozen hell. Now, instead of reaping the benefits, the portal's summoners have no choice but to guard it and ensure a demonic horde doesn't invade their world.