First, a couple of comments about rebuilding Koln in 4th Edition. When I started the Koln campaign, Caius had only played a couple of sessions with the 4e rules, and I was not much more experienced with them. As a result, mistakes were made.
In his 1e incarnation, Koln was a fighter. Period. Even though Caius had developed some pretty decent houserules regarding multiclassing, I don’t think Koln ever picked up a second class. Moreover, it was a big part of his character conception that Koln should wear plate armor. And in 4e, most fighters don’t get plate without a feat. But Koln was also supposed to have a dragonmark, which took up his level 1 feat slot. So if he wanted to be a fighter with plate at first level, his only option was to play a knight.
If I was to do it now, I would give him a dragonmark within the story without making him take the Mark of Finding feat. I was already giving him the Know Direction cantrip using the Dark Sun rules, so I could have made it work within established cannon, and built a regular fighter with plate proficiency. But I didn’t know the system well enough to know what things I could mess with, and what would have unintended consequences later on, so I stuck to the rules.
When I was designing the first session for Koln, I wanted to get into the back story. There was a part of the back story that I wanted Caius to know, but didn’t want Koln to know. And the backstory was interesting enough to play, except that Koln was not yet born when it was happening. So I decided the first session would be a prologue.
I had Caius play Lubash Tharashk, a dragonshard merchant in Karrnath. I built Lubash as an 8th level berserker, because: (a) I wanted to give Caius a taste of what characters could do at a higher level; (b) Lubash was an half-orc, and would traditionally be a type of barbarian; and © the berserker had a defender’s aura similar to the knight, which would give Caius an opportunity to get used to the mechanic.
The story I was going for was, Lubash is travelling in a coach with his pregnant daughter, who is crying. The coach is attacked a vampire, the coachman and horses are killed, and then the vampire attacks Lubash and his daughter. Lubash fights it as best he can, but dies, and the last thing he sees is his daughter being attacked by the vampire. So I start with a good fight, and a mystery, and then jump ahead to the main story with Koln as a young man.
The problem is, Lubash, as run by Caius, proved to be an able fighter despite being quite under-optimized. The vampire was an 8th level elite monster, and I expected it to do very well against Lubash and his pregnant, equally suboptimal, second level ranger daughter, particularly because I knew Caius would use the defender mechanic rather than the striker mechanic in order to protect the daughter. However Caius has a knack for strategy, and using the daughter as a flanking-buddy, Lubash beat up the vampire pretty badly. The vampire was forced to flee.
So, now what? Well, the vampire has a healing mechanic using his blood drain power, and they are in a town, so the vampire goes hunting a nice family of human minions. Screams ensue, Caius figures out what is going on, so Lubash and his daughter try to find a place to make a stand. Fortunately I had an interior map for an inn handy, so I dropped that onto the VTT map in time for the vampire to track them down. I didn’t want to repeat the vampire-flees-and-recovers-by feeding-on-human-family thing all night, so I added another vampire buddy.
From that point on, the timing of the combat worked out nicely. Lubash died on cue, just in time to see the second vampire slashing up his daughter’s face.
Railroady? So what? Lubash was built to die. Caius had no attachment to him, and it didn’t really remove his agency, because he got to control how Lubash died. Caius got some backstory, and enjoyed himself much more than he would have if I had given him a sheaf of notes to read instead. He became really invested in the character of the daughter, which would prove to be important later on. And he had a free trial run with the defender’s aura mechanic. Win-win.
For those who want the back story to the back story, here is the spoiler. Lubash is Koln’s grandfather, and the daughter is Anika, Koln’s mother, who is pregnant with Koln. The whole family are half-orcs, most of whom can pass for human. Anika left House Tharashk in order to marry into the ir’Koln family, as required by the Korth edicts. The ir’Kolns are a Karrnathi noble family with substantial holdings. King Kaius disapproves of the marriage because he does not want a dragonmarked house gaining influence in Karrnath through strategic marriages.
Kaius pressures ir’Koln to call off the marriage, but ir’Koln is in love and he refuses. So Kaius forces the issue by turning ir’Koln into his vampire spawn, and compelling ir’Koln to obey. Ir’Koln has no option but to obey, but he is still enamoured of Anika. Having lost his conscience in the transformation, he gives in to his base instincts. If he can’t have her, he will fix it so no man will want her. He creates his own spawn, and orders them to find her and disfigure her face.
So now we have the elements of the Koln back story. Koln has lost not one, but two birthrights: the first when his mother leaves House Tharashk; and the second when his father fails to marry his mother. What is more, according to the Korth edicts, he cannot claim both. He can either ask to rejoin House Tharashk, or he can try to claim his noble title.
You can find the session summary here (the italicised portion is a modified version of my notes for the session introduction).