The way a party is going to be adjusting to a backstabbing murderhobo is to throw them out of the party at the earliest convenience. It’s the only realistic outcome. If you want your character to be a part of the party, it’s your job to come up with a backstory and personality that makes them willing to work with the party, not the others’.

The reason all of this is skipped on a meta level is that most people want to get to the actual adventuring instead of trying to figure out one good reason why they’d ever keep someone’s unique evil snowflake in tow.