Every time I come here and see this thread at the top, it reminds me how much fun I had writing in this universe.

Usually war-torn Equestria, a wasteland all that's left of their once beautiful country, foals growing up too fast because there were no grownups left to hunt for food. And the immortal pony they might meet, who inscribed their own soul into the fabric of the edge of the universe; no longer in fear of death but also never entirely in the present, as part of them is literally outside the universe they're living in. And there there's the transfers, where he blinks, and finds he's wearing the face (and all the rest of the body) of his murderer, who was a pegasus mare, staring at the back of his head through a sniper scope.

Or the interdimensional traveler who managed to use the trip to achieve some version of godhood at the cost of his sanity. The schizophrenic superpower all that's left to defend his new, funny looking little friends from ill-meaning invaders, so long as he can keep track of which voices in his head are from his damaged mind, and which ones actually are from telepathic ne'erdowells.

Hmm. Insanity & immortality are my key themes?
...That's crazy, though.