Back when humans and pokemon fought side by side to dominate Ransei, a swordsmith sought to create the ultimate blade – one so sharp that it could cut through even an Aggron or a Rhyperior. He was able to produce an immensely sharp edge by experimenting with a mixture of origami paper and folded steel, but succeeded more than he intended to; the blade cut even the hammers with which he sought to pound it into a single sword, leaving a conjoined, impractical mess of blades without even a hilt to safely hold. Perhaps one blade first slashed the barrier between our world and the world of spirits – for the assembly began to move around like a living pokemon, and spoke the name "Kartana", before it cut open a rip in space-time.
It is not unreasonable to regard Kartana as the creator of the first recorded Ultra Wormhole, for the vacuum it opened transported not only its creator but his whole province, warlord and all, to a land inhabited only by an abundance of trees. Yet apart from those few people with friends and family elsewhere, those transported by Kartana did not mourn their fate, for land on this planet was abundant and arable, and no new warlords could follow them there; for an agrarian, peasant society, the Ultra Forest felt like paradise.
The man who forged the first Kartana would never forge another sword, but that did not mean he grew idle. In a development paralleling our own world's, battles between pokemon in the Ultra Forest evolved from a life or death affair into a popular hobby, and this meant there was no more need for swords. And yet, even while they worshiped the original as a god, everyone begged its forger for a Kartana to call their own.