However, let's take them in order.
The Skeletonites are one of those jokey factions for fans of props in Forever Knight—in this case, the peripatetic skeleton that decorated the set for the morgue. Les Chevaliers de la Nuit ("Knights of the Night") are a faction for fans who enjoy riding. The Lonely Hearts are a small couple faction for Natalie/Vachon. As for the fourth faction...well...! Its members are, in a way, universal. However, as a faction, they are, I think, unique to Forever Knight fandom.
Although the articulated skeleton was in one or another location in Natalie's office in all three seasons, we never really got a good clear picture of it. It was set decoration. Nevertheless, it did have its fans—if only with their tongues firmly planted in cheeks that their inamorato had long since lost. This did mean, though, that a screen capture was out of the question.
I therefore googled images of skeletons, eventually settling on a skull. To emphasize the humorous nature of the faction, I topped it with a topper. The icon is then finished off with a morgue-tiled background and a logo created using a "skeleton" font in which the letters are made up of stylized bones.
Les Chevaliers de la Nuit:
I don't know how active this group ever was. However, just as the Cross-Stitchers loved both Forever Knight and embroidery, so the Chevaliers were into riding.
Of course, Nick is seen in several episodes riding in flashbacks; so it was simply a question of finding a suitable screen capture. A bit of googling located a night scene for the background. I also added a made-up faction symbol composed of a sword and a horseshoe. For those who'd like to see it in detail, this is a larger version of it:
The sword that I used in the faction symbol is the same one that I have been using for Nick throughout this series of icons.
The Lonely Hearts are one of those small couple factions that were, I think, created more out of a sense of completism than anything. Of course, Natalie and Vachon do make a pretty couple, but I'm not sure what they have in common. (United by their long wavy locks? Long chats about hair conditioner?) I dare say that a few people wrote stories about them; but it's hardly the first couple faction to spring to mind.
I tried for ages to combine one or another screen capture of them with a large teardrop in the background over which I set the logo. Tears did strike me as a suitable motif, given the "lonely" in the faction name. Sometimes, I set a tiny heart inside the tear. Various backgrounds were switched in and out.
Well, that didn't work! So then I tried a large heart as the central motif—as if I hadn't done that before!—with smaller tears raining down. Various backgrounds. Didn't work.
So I scrapped most of what I'd done. I kept the logo and the tear; but I found two completely different screen captures and a different heart. I also created a new gradient to be the background. For those curious to see the symbol a bit larger and sans lettering, here it is:
I decided in the end to try a so-called "country heart", i.e. one that curves at the bottom. I flipped it in order to create a pair, back to back. These are lonely hearts, you see: they do not look at one another. Also, as you can see, they...um...weep.
The Wallflowers are a very odd faction, indeed. In most fandoms, people who do not chat on line, post to lists or communities, or write stories or draw are known as "lurkers". However, in the late 90s there was a small group of fans (notably Maddog and Rasto) who adopted the name Lurkers. As they were quite active indeed, not least in a couple of wars, it followed that "lurkers" and "Lurkers" were two quite different things. For a while, therefore, Forever Knight fandom seems to have used the term "wallflowers" for non-participant fans.
Well, a faction for Wallflowers is just as perverse as a Die-Hard faction for people who refuse to join factions! Nevertheless, there it is on the faction lists—or at least the longer lists.
For their icon, I composited a nice garden wall with a misty garden background and a clump of wallflowers in the foreground. The logo is a floral one, though you can't really make out the tiny flowers on the letters at this size. (Wait till I post the enlargement.) And I also made a dear little faction symbol.
A bashful little blossom. The basic flower shape came from Clkr.com, though I coloured it, gave it a face, and tweaked it by enlarging the centre so the features could be seen.