I'm trying to track down a short story regarding an advanced civilization that has the capability, for the sake of personal entertainment, to create virtual universes to explore and be entertained by evolving scenarios.
The main character and his friend each have a machine that lets them individually create worlds, foster evolutionary paths and wonder at the results.
The friend was somewhat callous in that once his world was populated and civilized, he would create a total destruction via a meteorite hurtling to the planet's doom. The main character was far more gentle and caring, resulting in a early civilization, but he was still upset at the violence and attitude of his creations.
There was an option to enter the v-world, but it was highly discouraged due to the dangers. Regardless he took that leap and was not seen for days. When his friend and others eventually found him when he returned, he was near death with a crown of thorns and puncture wounds on feet and hands.