Wulbren Bongle
a true rebel dies for his cause
Wulbren's Cause & True Believers
Wulbren is a devout Ironhand follower, but he is also a zealot. There is a flag in the code: "SCE_GnomeFollowUp_Knows_Wulbren Zealot" and its accompanying devnote: "Player knows of Wulbren's zealous plans." While religious affiliation is almost a given, as stated in EGP:EFR, "only zealots and clergy venerate just one deity." His hatred of the Gondians is thereby exacerbated by this zeal, whereas most people can exist with the worship and appreciation of more than one god. Given that Gond is not actually of the gnomish pantheon, and prior to his arrival and gifts in Lantan gnomes weren't big followers of Gond, there are extra complications to Wulbren's relationship with him and his followers.
Beldron says that "Wulbren has a way of attracting true believers" to their cause, and other than Wulbren himself, there are a couple of examples of true believers in the Ironhands. Philomeen and Thulla are good examples of this. Philomeen's thoughts indicate she plans to die for Gaerdal Ironhand, and one could easily see Wulbren feels the exact same way about the cause: it's all or nothing for them now. He's given up the proper channels and writing to the High Artificer and decided he's going to take violent action to "make them listen."
Wulbren's Family
Wulbren's existing named family are Wolverforce Bongle, his grandfather, and Antunio Bongle, his father. Wulbren also has an unnamed mother mentioned in Barcus' Log.
Wolverforce Bongle
The documents on Wolverforce Bongle are one of the few things that provide more information about the Ironhand-Gondian conflict in the actual game. Wolverforce is mentioned in the book "Ironhand Gnomes: Our Grievances," and although the book is Ironhand propaganda painting them as victims, some of the information is useful for background.
Initially I thought this was the ravings of a madman, but with the information I've learned from Elminster's Forgotten Realms about "Becoming a Priest" section, I've decided to write Wolverforce's experiences as true. Other reasonings for this are that Wulbren does find the formula for runepowder, and as the gods have control, I don't think such a thing would be possible without interference. The book "Runepowder and the Modern Gnome" didn't seem like it was written by Wulbren, unless it was written by a writer who was less familiar with his voice. I think it was written by Wolverforce and have designated him a higher member of their order, functioning similar to a priest although their faction is different from other religious orders. It would also make the cause of getting back at the Gondians matter more to the rest of the BG3 faction if Wolverforce was a man of high standing and losing him was a major blow.
Antunio Bongle
Antunio's grave marker in the Lower City Graveyard says "Antunio Bongle - Proud Father of Wulbren, Remembered by the Son." Because Wulbren's mother is unmentioned in the marker, I chose to write Antunio and his wife as being separated and made it a little bit like the conflict Barcus and Wulbren have with each other as a cheeky repeated history kind of problem.
Others
There are no mentions of other family members, but if Wulbren is dead, in Moonrise Towers Barcus says he must inform Wulbren's family. He also says the city is the priority, so it's likely they live there somewhere (even if it's just the outer city areas--I've always written the Ironhands as living in Sow's Foot while working secretly in Rivington). It's possible "his family" is just his mother.
Wulbren's Life in Baldur's Gate
This is one area where the writing seems confusing and conflicting. Wulbren says the Ironhands are banished, and they work in a secret forge thanks to Gyldro. While I thought this meant he couldn't go inside the city at all, without some sort of special permission, Barcus says "Wulbren made his life there." if Wulbren is dead. He has many comments about dealing with Wulbren's family and affairs in the city. I also don't understand why Barcus is the one who would be organizing his affairs if Barcus and Wulbren haven't spoken to each other in a long time (and Barcus does say he doesn't even remember the last time they spoke). Wulbren's father is buried in the Lower City, but this paragraph from Descent into Avernus claims this is not common for anyone but the wealthy:
The value of land and sheer population density in Baidur's Gate means only the wealthiest patriars canafford to bury their dead within the city, interring them in catacombs beneath the city's temples or in family crypts on their own grounds. For everyone else. there's the ignoble Shrine of the Suffering or the scattering of cemeteries outside the city. The largest of the latter is Cliffside Cemetery, located in the Tumbledown neighborhood and employing many local residents as gravediggers, stonemasons, morticians, and professional mourners.
That's an easy one to skip over, of course--there are unmarked graves in the cemetery and it seems like average, every day people are buried there, so this fact was changed for the game. But if Wulbren isn't allowed within the city's gates, Antunio's burial makes no sense.
As for another confusing aspect, the devnotes claim Wulbren is incredibly influential in Baldur's Gate when he tells you he knows powerful people there. Wulbren would likely be able to get strings pulled for his father's burial in this case, but it leaves us wondering about his true relationship with the city and its citizens.
Wulbren's Relationship with Barcus
Wulbren's Spattered Diary indicates that he cared for Barcus before leaving, and a few lines from Barcus and Wulbren indicate their relationship is more complicated than either is showing. As mentioned in my BG3 summary, I believe Wulbren was carrying the amulet from Barcus until the events right before the game, and this would be an odd thing to do if he didn't care (unless he's grown used to it and it just didn't matter if he did or didn't wear it anymore). My favorite line from Wulbren that shows he thinks he's doing the right thing by keeping Barcus away is after you call him a prick. If the player says he was being harsh, Wulbren says "Perhaps, but sometimes cruelty is a kindness. Believe me, Barcus would do well to keep his distance.”