I was away for a long while during this summer, as I spent a month in Urbania, Italy studying the Italian language and Italian Opera. I had to leave my group(s) behind for a full month while I was away and during this time one of my players, who we'll call "Von", decided to give it his first shot as a DM in my absence and playing in my world that I had hand crafted upon 4e's creation.
I didn't mind this at all, and I encouraged it. It would be good to have another player see what I had to do to set up a game for them. I was excited.
They started off a little late though, 2 weeks into my monthlong trip to be exact, and ultimately I was asked via e-mail if I would like to play in the game when I came back. "Von" had been doing 'ok' with a few exceptions in my book:
1. He used his former character (a 30th level warlock) as the primary quest giver
2. Bullied most of the player characters into the quest
3. Gave this character (whom they had all played aside of) extraordinary abilites and near godlike power, and with that came the arrogance and snooby attitude.
4. Proclaimed that since that time he had started an academy for spellcasters (coinciding with the White Lotus release, bravo for using material I say!) and used that as his base of operations.
The party was mostly unaligned with the occasional evil character, but all of them felt the angst towards this character immediately. With this said, the jist of the main quest was a Planar Scavenger Hunt for items so that this character could make an 'item of great power'.
Now, the players had been bullied enough by this point when I arrived and I looked at where the pary dynamic was going immediately. To make the transition easier, I tipped the scales further creating an evil hybrid Rogue/Sorcerer, Gnome. This way, the pary didn't have to deal with me as a wildcard and we could continue on with what they had set out to do.
In the end, we decided that we would not be giving these items back and decided to give them to another organization. In addition, to obtain the final item peacefully we made the decision to offer the sigil sequence to the teleportation circle to a rival and much more evil organization. Ultimately, we were killing two birds with one stone.
"Von" would have none of this it seemed. He proclaimed that these items gave his primary quest giver the ability to see 100ft around the items wherever they were, and that he knew exactly where and how to get to the ultra hidden "Evil Spellcasters Lair" was. In the end, he aimed to kill us all by using his character's epic desiny by claiming that he would become a Radiant Star (see Radiant One Epic Destiny) in the middle of the spellcasters lair.
He took the items off of us without attacks or saves, and proceeded to go, in his words, "Supernova". For 30 minutes there was no action by the characters only a narrative by the DM explaining how things had totally turned against the players due to his former character.
With some quick thinking and being hell bent on trying to save some aspect of this game I used the one thing I could when he stopped for a few seconds, proclaiming that I was going to use the exodus knife to draw a door for us to sneak into.
He spent several minutes trying to figure out a way beyond this, but could not. In the end, the players were safe but with nothing to show for our efforts. "Von" was angry and agitated by what we had just done and quickly packed his things and left without more than a few sentences.
Railroading and inflexible DMing caused a personal conflict to arise that made a DM vs. Player situation. I'm not a fan of that. But, though the final actions it was assured that these characters could be used again.
The campaign ended that night and I hashed things out with "Von" a day later, who was still fuming about the incident. It was all sorted out and we established what I will say next.
To DM's, be careful with how you use former characters, and allow the PC's the freedom to do as they wish. If it is something you don't see eye to eye with, do not give them an ultimatum or an unwinnable scenario. Present them with a reasonable challenge and play it out. See what happens. Its a game, so play the game.