AlKim: I used to reuse names in the past, which sometimes lead to some complex and rather boring weirdness which bothered no one else but myself, so I abandoned recycling at some point.
Zchinque: What kind of complex and boring weirdness? It sounds intriguing.
Here goes, since you asked. Everyone else can skip this post and save themselves a few minutes. The tl;dr version is that I have used the same character - or rather, used the same name for entirely different characters - in numerous works, which is a bit like writing four books, all in a different setting and with totally different characters, and always calling the protagonist Jack Bauer.
A history lesson first. In upper secondary school we had some boring lessons so a friend and I occupied ourselves with comics that were usually based on video games but with one or most characters replaced by original ones. I would like to stress at this point that I have never been good at drawing nor writing a script, so the stuff I produced has aged poorly and hence I won't show my work. Most of it may have ended up in the bin at some spring cleaning anyway, and I only know for certain that the Resident Evil 4 thing survives.
I drew a whopping three pages of an Icewind Dale comic; it was supposed to span the entire game, but what little I scrawled together only cover a timespan during which the protagonists arrive in Targos and bicker about. I abandoned the idea of covering the whole game because 1) my skills lend themselves poorly to battle scenes, so I would have to focus on 2) the story, which is pretty poor in Icewind Dale and so I would have to think of original content to make the comic more interesting to read, but that didn't matter because 3) there were
five protagonists, a pain in the ass to handle in those three pages during which nothing happens, let alone a bigger project.
I digress. In any case, one of the five characters was Chelsea of Waterdeep, a pale druidess with a Greenpeace attitude towards nature. I wound up recycling her for Neverwinter Nights, character class and all. I drew a whopping two pages of comic, intending to give her a more tempered nature (pun intended) and a sidekick recycled from Icewind Dale. Since I wouldn't have to worry about making the storyline compelling anymore I could focus more on the characters, both major and minor, and give the dialogue more thought.
Unfortunately I drew the two pages of comic before I had finished the game. At some point I realized I sucked at playing a druid and binned the character, dooming the comic in the process (since I would have little idea what a druid was capable of). I made a female cleric instead, and, lacking a good name, wound up naming her Chelsea as well. So now there were three Chelseas of Waterdeep; the fundamentalist environmentalist from IWD, the less extreme urban druidess of NWN and now a cleric. Her personality was becoming more and more splintered, but of course no one was bothered by this because they never played the game nor read the unfinished comics.
I got some sort of bout for writing fiction at a later moment in life. I never finished anything worthwhile and everything I ever wrote has vanished with failed hard drives and such. Anyway, once a friend (incidentally, the same one I drew comics with) realized this he asked me to write some fantasy, preferably with a long dialogue, so he could revive his passion for comic drawing again. I set to work right away, with him watching over my shoulder. I recycled the aforementioned Icewind Dale sidekick (this wasn't a problem because he had been based on myself all along), made him the focus of the think-as-you-write-along bullshitting and wrote about him going about his business in some city, eventually stopping by in the tower of a sorceress to buy some potions and borrow a sword spider. As per request I described the surroundings and the sorceress in some detail, but couldn't think of a proper name off the top of my head so I just put “X” where her name should've been. After about a dozen X's my friend asked me to replace it with a real name (it's quite boring to read a dialogue where one character is called X), and I realized the relationship between the characters was exactly as I had intended it to be in the failed Neverwinter Nights comic, and so the old name got recycled again. Now the fourth Chelsea is a sorceress who looks very different from the druidess, studies spiders, summons supernatural spiders to her side (or, more appropriately, between her and the enemy) in battle and, like most self-respecting stereotypical mages, lives in a tower, albeit hers is built mostly underground with just a ten-foot-high disc jutting out of the soil.
Apart from being able to cast spells, the four Chelseas differ so much that I can't think of a reason for them to have the same name.