Should not have talked alignment with a friend of mine. I'm sure people are tired of hearing about this guy, but this time he will end up being an outright asshole to the group.
I mentioned a somewhat obscure lawful good god that is very knight templar in behaviour. Paladins that follow him can get away with killing anything that's not good simply because they are not good. Even if they have surrendered and are begging for mercy, or are otherwise completely harmless.
He's going to act in a psychotic, practically chaotic evil manner in an as of yet undetermined campaign, simply because there will be no repercussions for his character, and he will be able to get away with it. He will act this way towards other players as well, which will cause shit. Purposely starting in-party conflict will hopefully not be allowed.
I don't see a problem with being HAMMER OF THE LAW out to EXECUTE IN THE NAME OF JUSTICE, completely irrespective of whether such BASED CONVICTION exacerbates the problem, or fixes it, or replaces it with a new problem. A la Judge Dredd, or someone who subscribes to virtue morality and just so happens to also be a walking god of war.
Providing this actually involves RP of course, and isn't just "detect evil, now I kill."
Though then again, DMs can always just have a good person show up as evil on such a detect evil test just to screw with aforementioned paladin and make them fall if they deserve it.
Sirus's idea's also pretty good. Follow the LAW and not kill all EVIL peasants, or break the LAW and come afoul of GOOD people trying to enforce the LAWWWWWW.
I seem to recall one fatguy sess where two of the members of their party, one a paladin and the other a dwarf had an undying hatred of orcs. See an orc, kill an orc. And there was no arguing over whether to kill an orc child was an evil act, no you kill that orc. They had both just slaughtered another warband of orcs when the paladin was knocked over a ledge by a charging orc. The dwarf caught his arm before he fell for good. The paladin's helmet fell off, revealing for the first time just what the paladin was. The paladin was an orc.
Urist McDwarf lets go of his hand. And to paraphrase fataguy anon:
>our pfw
:OOOOOOOOOOOOOOOOOOOOO
Situations can always be spicy when you have the right ingredients