Alaric’s big secret was already pretty well known by the time I began playing him (he and Brianna had a certain kid named Alarion and the whole reason Carlotta and Sherrod went on the Night’s Grove trip with him was to figure out what to do about it in relative privacy) and if that wasn’t enough, it actually got aired out at the Assembly of Peers by Marcus the one time. (Marcus getting banned from the next AoP for a made-up procedural violation was 100% Alaric retailiating for that, lol.) That said, he did know straight from the drop that neither Alarion nor Alaric III were dead because they didn’t show up in the Shining Lands to yell at him while he was under the Exsilium Noctis, though the latter also wasn’t a secret for too too much longer (lotta other people got visions about that). His other other secret was also not really much of a secret in that he needed soul healing not to go cuckoo for cocoa puffs again, so no offing the NPC Queen since she was the only one around who could do it! (This was also instituted so as not to a) not let the alliance with the Nox backslide since the plot had turned out going this way and b) not touch off the mother of all IC/OOC catfights by having a single PC King in play. I was 100% on board with this.) In a lot of ways Alaric’s real big secret was that the admin staff never expected anyone to get him fixed in the first place, hee.
Ferrando’s secret was that he was a Red Warden from the get go but started play on the outs with Wolbrand (the Red Warden version of the secretly evil NPC placeholder org leader, though Wolbrand wasn’t really capital-E evil just so much as a big jerk who wasn’t very concerned about keeping his operatives alive IIRC) due to a mission gone bad. Said mission involved Ferrando using a one-time-use magic healing widget to save the life of a conwoman captured by the Smiling Shadows after killing the Shadows, instead of leaving her to die and tailing the Shadows back to their hideout like Wolbrand wanted. Said healed conwoman took up a new identity as Selene after recovering, ergo Ferrando got himself hired at the Whisper House to keep an eye on her if the Smiling Shadows went after her again. This plot hook never actually went anywhere since there was never an active Selene before I got Alaric, and after that if I had a scene with Selene it was as Alaric because he kind of took over all my playtime. According to Apos’ AMA this was all tied into the death-of-Genevieve plotline.
I only ever made one OC, Vayne, but I didn’t really find a groove playing him and gave him up to the roster after two months. He was fairly successful as far as donated-roster characters go (he got promoted to Legate!), which was neat to see. Anyhoo his secret was that his reflection in a mirror would occasionally serve as an informant or otherwise give him advice when he was alone.
Strictly speaking I was also the first Jan Kennex but other than getting her initial starting skills set up I barely got out of her @rs period because a few days after I took her up the Alaric apps opened up. Whatever her secret was, later players would have had to set it up.
I also picked up Fairen for the last month (sort of hilarously the only character I ever @org/disafavored as Alaric because of complaints about that one player who could not have a civil IC disagreement with aaaaaanybody to save his friggin life), whose nominal secret was that he was haunted by the ghost of his older sister Hianora, who maintained her control-freaky advice tendencies after death. Though Fairen’s real secret was basically that ex-Metallic Adept and current Seal-keeping-Baalphrigor-snoozing Nickel was hiding out in his basement (which strictly speaking was an extensive network of caverns) back home under the Leaholdt, since House Leary was basically founded primarily to give the surviving remnants of the Nickel Guard the political authority to raise an army and use it to keep Obsidian cultists out of the territory surrounding the caverns and such.