So... on my gaming group there's this new(ish) guy. He presented us with Pathfinder, a place to game and a Paizo-made adventure.
At first we were very interested in those sweet new system and all. But as a GM he was the "I'll show you how well I know this game and you suck at it" kind of guy. I think he went a bit far on the minmaxing thing and... well, he was more happy beating the players with his buffed NPCs than actually GMing.
That pre made adventure turned to be meh to the group, because he basically read from the book, line by line, put the minis on the map and we fought. It was very mechanical, very.... boring, really.
So the group lost interest and once our old GM (let's call him Oldy) got back on his feet and revived our old, dear, campaign... well, we were a happy bunch of people (very into it and awfully close to our characters).
Of course we asked if the new guy wanted to join our group, he accepted, he built his character and things started to fall apart.
Basically the guy had this great vision for his character: and evil elf with a powerful animal companion, but being quite powerful himself, the character could do everything... alone (with a sprinkle of cruelty, since he was evil).
We were running a Good alignment campaign, with well balanced roles (a fighter, a thief, a wizard, a sorcerer...), Oldy, the GM, said "look, try to tune the evilness down", but the new guy started to compete with everyone at the table: measuring stats, doing solo missions, questblocking, cockblocking... Not to mention that one time (at the band camp) when he started to go all "WOHOO I ROLLED HIGHER THAN EVERYONE SUCKERS!!1ONE"
Bottom line is this: we lost 3 players, Oldy has no idea what to do anymore and asked for my advice since "happy nice chat with a player" isn't working. So I'm asking you guys:
How do you deal with those uber competitive players? How do you handle the One-Man-Group build characters? And what if the guy is just being a jerk?