So I'm going to try to run a solo planescape game for someone who's only ever played Planescape: Torment. His character got drunk and thoughtlessly seduced a nobleman's fiance then wound up in bed with her before he realized what he was doing. Yes he's pretty charismatic... and she didn't like her fiance. Anyway, they decided it was time to leave after they almost got rubbed out by his bodyguard, so he devised a plan of lowering her out of the second window with a rope and following after her. Unfortunately the window was a portal. So basically, she's fallen through a portal and he's been pulled in after her by hanging onto the rope.
I need some ideas for how to describe his first view of Sigil. He's from a fairly diverse material plane world that's technically set in the 4E cosmology, but we're just sort of ignoring that and setting it in 3.5E planescape. It's play by post, so I want to make a really spectacular and atmospheric first post, but I want to drop them in the Hive to better facilitate... fun stuff.
Oh yeah. the character is a gnome.
Also, I wanted to make his sword intelligent, just for added weirdness. I was thinking of having the woman get trapped inside of it or something like that and that's be the personality, any ideas?
Well, for explaining the city to someone who's never seen it before, my two favorites are 1) sudden, jarring incompatibility with everything they've ever known, or 2) slowly dawning realization that "we are not in Kansas anymore" and Toto is probably an Abashai.
For most people, no matter where they're from or what they're doing or what else is happening, if you're dropped in Sigil for the first time the sight of the ground above you on the ring is going to be taking first place in your mind. If you're from the prime you have a certain assumption that there will always be either blue sky, night and stars, or clouds above you, not shops, bars, and marketplaces. After that I'd stress the smog, the razorvine, the hodgepodge of architectual styles and building materials, and finally move on to the inhabitants. Don't go all out showing them everything at once, though. A Clueless will always have something new to be amazed at and to make false assumptions about. Feed them strangeness slowly and let them react.
As for the magic sword idea, I think it would work well. In a one-on-one game it is always good to have an NPC that acts as the GM's voice (as it were) and this gives you a way to do it that avoids the NPC that eventually becomes the GMPC. And if you go with the girl being trapped in the sword, I would love to hear the conversation she has with the gnome the first time he tries to use her as a weapon.