Looking for some ideas for a twisted/dark twin version of the Dragon Slayer mentor spirit as one of my player's is straying down a darkish path that is very much antithetical to the dragon slayer.
I am just not sure what way to go, and looking for a few ideas.
For a dark side version of a Mentor/Totem, take the description and twist it in upon itself. Hang on, I need to look up Dragonslayer . . . okay. For Twisted Dragonslayer, change the definition of 'fun' - like, for example, the new idea of fun involves inflicting pain, possibly shedding blood in the process. Loves a good party - like a BDSM orgy. Big brother aspect - say, like Bill Paxton's character in 'Weird Science' (not the best example, I know, but it's a start point). 'Dragonslayer fights such modern-day monsters as crime, pollution and corruption' - so, under the dark interpretation, what counts as crime, pollution and corruption? You could end up with a seriously nutjob crusader-type.
The prime mythological example of Dragonslayer is Thor/Thunor from Norse/Germanic legend, but there are others, if you want to get more specific. Just think what Thor appears like to an irreconcilably hostile viewpoint/perspective.
That's pretty much exactly what I was going to say. Take the mentor and just corrupt it. those are some good ideas. Some other examples (to add to Long's list) would include:
Mentor's 'version' of ______ is...
• Fun = involves inflicting pain, possibly shedding blood in the process.
• Loves a good party = Pit fighting. Opium den.
• Big brother aspect = Bill Paxton's character in 'Frailty'.

• A crime = not finishing off a fallen foe or an injured innocent (wouldn't want to cause needless suffering).
• Pollution = "of the mind", anyone who doesn't agree with a certain aspect of the mentors new outlook.
• Corruption = "of the spirit", anyone who would seek to 'pollute' (see above) the minds of the mentors followers.
you can see where this would also intrinsically change what the mentor considered "honorable" for the purposes of the mentor spirit disadvantage. Could be tons of (dark and twisted) fun.
Also -- Odin was pretty dark generally speaking. He would make a pretty good "dark dragonslayer" imo.