I'm in a D&D Homebrew campaign that allows pretty much anything as long as it is written online. We have one player in specific who is frustrating and decided at the end of the campaign, he would try to kill us all off.
The reason for this is his race and class. They happen to be a Terminator t-800, and this would not be a problem if it were not for the fact that whomever who wrote it decided they get an insta-kill and stop time.
I am much faster than him, but because of the DM, he has a 20 AC.
The DM is a pretty cool guy, but he says that me and the 15 people I asked about the character being op are wrong, and I need to stop complaining, or I will be killed off. I only have one person in the campaign who I know will help me, but they keep threatening me to not team up with him, or else, because they think I invited him to help me, even though this became a problem afterwards.
The DM is kinda like a sugar daddy to him, and will just give him what he asks for. When I pointed out that multi classing into hamon user can give me infinite spin, they got scared, and started pulling some **.
I also don't know he is not human yet, so I have to find that out somehow before I attempt anything.
TL;DR: Another player is overpowered and I can't deal with him because plot armor.
I probably should have mentioned this to begin with, I want to know how to beat them in-game, because talking just never seems to work with these people. Also, the anything goes part is kinda exaggerated, because he won't let you have universe destroying powers. I don't necessarily want to beat them in a fight, I just want to avoid my character dying, so it doesn't have to end with me teaming with the boss.
So basically, I want a scheme to keep my character alive.