I'm a fan of the targeted bait-and-switch, provided it's handled well, particularly for modern and sci-fi games. Where I think your GM went off course was mutating the one character. It's one thing to make a character thinking the game is going to be one way and changing course but it's quite another to invalidate a player's character concept before play even begins.
Bait-n-switch example campaigns that can work well:
The secret Horror campaign:
Set-up: You're cops. You fight crime. You play through several sessions establishing your characters and working routine cases: homicides, robbery, etc. Then things start getting weird. The vic is drained of blood. The suspect doesn't go down despite knowing you and your partner put rounds into the bastard.
Seriously, which is more enjoyable (i.e. scarier - cause that's what you want with horror): "We're going to play a vampire hunter campaign" and everyone shows with their Van Helsing, Buffy, or half-vampire knock-off character concepts or "We're playing a dark/mature cops campaign" and the characters discover through their own investigation that the crime family controlling the drug trade is a coven of vampires?
Sci-Fi: Front Seat for the Apocalypse
Set-up: The PCs are on a colony world and have their space opera or hard sci-fi characters ready. Then the aliens invade - and the colony loses. No space travel, no infrastruture, and no idea when/if help is coming. Oh, and did I mention the aliens have other plans for the colony?
Sometimes, in order to avoid meta-gaming or really shock the players at the start of the campaign, the bait-and-switch is the best vehicle. Turning a character into a vampaign over the course of a campaign is a storyline. Telling the player in session 1, "you were attacked by a vampire and are now his slave" without any input from the player is just a bad move.
Bait-n-switch example campaigns that can work well:
The secret Horror campaign:
Set-up: You're cops. You fight crime. You play through several sessions establishing your characters and working routine cases: homicides, robbery, etc. Then things start getting weird. The vic is drained of blood. The suspect doesn't go down despite knowing you and your partner put rounds into the bastard.
Seriously, which is more enjoyable (i.e. scarier - cause that's what you want with horror): "We're going to play a vampire hunter campaign" and everyone shows with their Van Helsing, Buffy, or half-vampire knock-off character concepts or "We're playing a dark/mature cops campaign" and the characters discover through their own investigation that the crime family controlling the drug trade is a coven of vampires?
Sci-Fi: Front Seat for the Apocalypse
Set-up: The PCs are on a colony world and have their space opera or hard sci-fi characters ready. Then the aliens invade - and the colony loses. No space travel, no infrastruture, and no idea when/if help is coming. Oh, and did I mention the aliens have other plans for the colony?
Sometimes, in order to avoid meta-gaming or really shock the players at the start of the campaign, the bait-and-switch is the best vehicle. Turning a character into a vampaign over the course of a campaign is a storyline. Telling the player in session 1, "you were attacked by a vampire and are now his slave" without any input from the player is just a bad move.