Author has written 1 story for Ranma, and Fate/stay night.
I have gained my Master's degree in economics and am now desperately trying to find somebody willing to actually hire me, as apparently its all about the job experience and not the education and guess which one I focused on? In any case while this should theoretically mean that I have more time to write, I'm generally too stressed out from the job searching to get as much writing done as I would like.
About my story Chaotic Fate:
I have a habit of thinking up stories in my head when I'm bored, generally based around whatever story or show I was reading or watching at the time. This story was the first one I was able to look back on and decide that it wasn't some wish fulfillment piece of crap, but instead something that had a good plot and mostly kept everybody in character.
Since I've already thought out this story that means that I know where I want everything to go and have already fleshed out a lot of the major scenes.
Ki vs Prana and martial artist vs magus: I hint at this in Ch. 1&2 and will go more in depth no the future, but I'll go over it here as well. Ki is the same thing as od, the energy within a person's body and chi is the same as mana, the energy in the outside world. I'm essentially saying the life energy a-la ki and chi is just another term for magical energy a-la od, mana, and prana. This means that martial artists (the good ones) and magus use the same energy, just in very different ways. I plan to go into this a bit more in the story further along the road so I'll leave it at that for now. This is one of the reasons why Ranma, a non-magus, was able to summon Saber.
Ranma summoning saber: Ranma is able to summon saber despite not having an artifact of her's to act as a catalyst since, as mentioned both in the story and on the wikis I've checked, artifacts are just one form of catalyst to be used when trying to summon a specific hero and aren't required to summon a random hero. The Masters are picked by the Grail, not by whoever happens to have an artifact. Without an artifact a Master summons the heroic spirit most similar to himself, at least that could fit into whatever classes are left at that point. So Ranma was able to summon Saber because they are very similar to each other. Also because I'm the author and I get to do what I want.
About power levels: I'll be hinting at this in my story, but since I know how important it is for some people I'll spell it out here. In terms of skill and physical ability Ranma is on par with most of the Servants. If you've paid attention to the stuff Ranma pulls off in the manga you'll see that if anything I'm selling him a bit short in terms of physical ability. Of course I'm upping his skill a little bit to be better able to deal with these heroes who are at the pinnacle of skill with their weapons. I should clarify that this is without taking into account noble phantasms; which Ranma in general just can't compete with.
Since Saber has a strong Master who can provide plenty of prana her stats are going to be higher than they were with Shirou. I think this makes sense since it seems the stats are influenced by what areas the master is best in.
Let me know if you want me to do something like this for Ranma at some point.
Update 11/12/2012: Rejoice! I'm alive and even better I actually have a new chapter for all of you!