Kayle was actually inspired by, of all things, [a CPU fan]. I didn't even have much of a background for him at first, but managed to hack out a background and/or plot thanks to some help from a [friend] of mine. Before you ask, yes I am prodding her in the direction of Puzzlebox. Current estimate on an application submission is: the next extended break she gets from school.Soon-ish.
Kayle's certainly evolved from the one-off "generic shiny character" he was. He's got a past, motivation, and even a crush or three. He won't admit to them directly.
Before he came to Puzzlebox, Kayle worked for a streetdoc primarily designing, building, and helping install systems for various clients. He also claims he was the tri-state neuralstim champ for five years running, and so far nobody's argued.
The tech level present on Puzzlebox continually astounds Kayle with it's ease of use and complexity, particularly the cybernetics installed in some of it's residents. Notable examples of his admiration are Kehari?, Lysette, and Slight, all due to the extensive and/or extremely high-level gear they're packing. This is a purely technical form of admiration in the first two cases, the way someone would admire somebody else's computer or car, and the crush in the third case is fine with Slight's player, so nobody go freaking out about it or anything.
Kayle's straight. Really. Just because he thinks Indi, Torque, and Frostbyte are cute doesn't change that. Really, I swear. Okay, I lied. Kayle's straight, but he's also been pondering things like sexuality since he came to Puzzlebox. Feel free to try and get in Kayle's nonexistant pants.
Kayle's apparently a Gridshaman now. He's not quite sure what that means yet, but he doesn't mind. It helped him come to terms with Death, who's actually got a pretty neat (if morbid) sense of humor, and disentangle his personal timeline glitch. Plus he left a neat scorchmark on the ceiling above Downwarp square, which he decided to commemorate with a signpost marker.
Nikolai's Subjectivity Distortion Generator gives Kayle a headache whenever he's near it. This is unrelated to the radar distortion he gets from the Cyclotron Forest, and may or may not become a plot point. Long story short: Kayle's timeline-disentanglement had a side effect of leaving a sort of temporal "this just ain't right" sense behind (which has so far been mistaken for a really bad headache and a lingering Bad Feeling), and a minor temporal immunity; he gets echos of things he was involved in that never happened (see: [this wall-breaking log]).
Thinking of having Kayle come up with an ambulatory, semisentient, alcoholic beverage that enjoys being consumed. The basic idea is "big-titted vixen made out of beer", but customizable. Maybe I'll expand on it once I've gotten some sleep. Prelim writeup is done; need a name though.