The most innovative aspect of Lord of the Rings game Shadow of Mordor was its Nemesis system that had enemies being promoted after killing you.
Warner Bros patented its Nemesis system last year, so don’t expect this mod to become official in any way.
The Nemesis and Alternative Death System mod is available on NexusMods and makes “every enemy that defeats you into a unique Nemesis” to create “emergent stories of revenge”.