Dr. Shin was a scientist working for the Ishtar Academy on Venus. Along with researchers; Maya, Chioma and Duane-McNiadh, he undertook the analysis of the Vex as they had seemingly been present on Venus from before the Golden Age's commencement. These events took place before the collapse. After having captured a Vex specimen, the four scientists studied its capabilities, only to find that within the "Mind", the Vex had created digital simulations of the scientists "studying the Vex specimen" (this part may get confusing). They discovered that the machine had created digital copies of them within itself, studying a digital copy of itself, that was creating digital copies - so on and so on. Copies within copies within copies. Infinitely. The Vex had done this to simulate the scenario that it was in, in-order to predict its futures. The problem was - it became very clear that the digital copies of themselves had simulated intelligence as well. Think of them as being identical clones made in a computer that think that they have the same memories as the originals. This meant that the originals weren't sure as to whether or not they actually were the originals, or if they were simulations as well, that simply thought that they were the main bodies. In order to find out which researchers were real, they had to introduce the Vex to something that it couldn't simulate- something that was too complicated. The four researchers utilised the Warmind of Venus. Warminds are planetary defence AI that have control over countless arrays, satellites and doomsday weapons - all created through Golden Age tech. It would seem that the sheer amount of processes that the AI was capable of were too much for the Vex, so the scientists were able to identify their "real" selves by finding out which Warmind was "real". The Vex was able to physically simulate the Venus Warmind, but not its complicated coding. Moving on - the original Shim, Maya, Chioma and Duane-McNiadh managed to extract two hundred and twenty seven copies of themselves from the Vex's "Mind" as code. After consulting with their digital selves, they came to the conclusion that the copies could be put into the Vex network to explore, learn and record. The two hundred and twenty seven copies of each scientist were brought to the citadel on Venus and injected into the network. Following this event, the team of scientists were split up across other projects. Moving forward in the games, we may end up meeting a digital copy of Dr. Shim, or at least learn more about the Vex through his research. Hope this helped!

I've had a look. Nothing other than the exotic (that I could find) refers to the name, and the description of the weapon simply describes how it's used, so there are no clues there either. Sorry to say, but it appears as though we know nothing about Khepri. If anyone has been able to find a class item, artefact, piece of armour or weapon that mentions the name again, please let me know. Edit: I'll be answering the question about Dr. Shim separately because it's quite a large chunk of explanation.