When I was told by my regular and somewhat long-time Dungeon Master that our new campaign, following the two-year long one we had just completed, would migrate from the fun and flawed 3.5 edition of yore to the newer, sexier, and simpler 4th edition, I did what I always do when presented with a new and exciting RPG system: Immediately find the black sheep of the game's splatbooks and make a character from it simply because I know that it will be a particularly unique character. This same instinct is what led me to bring Skarn from the 3.5 edition sourcebook Magic of Incarnum into our campaign, which led to the species becoming an integral part of our homebrew setting. With 4th edition, ended up looking through the Heroes of Shadow book. Though I didn't know it at the time, I was doing the same thing as I had with the Skarn.
Damien was the first 4th edition character I ever made, and is memorable for entirely the wrong reasons. I only played him once. Damien was cool. He was a lot of things, in fact, but his defining aspect was that he was cool. He looked like Vampire Hunter D, but had all the charm and panache of a swashbuckler. He had a silver tongue and a lightning-quick blade. But no one liked him. Why? Astute readers will know that the vampire class in 4th edition has extremely little freedom in character creation, especially when compared to the rest of the system. The problem was not that Damien wasn't pulling his weight on the battlefield. The problem was that Damien had no reason to BE on the battlefield. Damien was an eladrin (high elf) who had once been a bit of a party animal. Then he had the misfortune of being seduced by a vampire and turned into a thrall. Luckily, his brothers and friends came to the rescue and slew the creature, freeing him from her control--though his vampiric affliction was incurable. After this, he mellowed out quite a bit, leaving his party days behind as he focused more on what he could use his newfound power and lifespan to accomplish. We were playing in the Eberron setting, which encourages player diversity in terms of race, class, etc. But we had a problem. Why would Damien be with the group? He had plenty of things he could do, like wander the world and do good deeds--but why here? Why with this group of individuals?
A more serious problem revealed itself to me as the session wore on: Damien's arc was over. He had already confronted the consequences of his recklessness, and had paid a dear price for his pride. He had come to terms with and accepted his own flaws and shortcomings. He had nowhere to grow, and nowhere to evolve. He wasn't a player character. He was an NPC. Now if that doesn't sound objectionable to you, you can go right ahead and play that type of character. But in my group, my DM and fellow players expect a certain amount of fluidity in our characters. We like to see characters grow and change, to rise or fall as the dice roll or the plot demands. But Damien had little to work with when trying to integrate him into the story at large. The only thing worse than a bad character is one who doesn't belong. Those issues combined with the fact that no one was willing to roleplay a character who was as relaxed and nonchalant about Damien's condition as he was proved to be a jarring clash of characters. So I swapped him out. But he's still in my worn green binder of character sheets. You never know when you might need a vampire.