I'm O+, which I believe is the most common blood type worldwide. According to the wiki, this should be true of me:
Best traits: Confident, self-determined, ambitious, strong-willed, intuitive, agreeable, competitive and athletic.
Worst traits: Unpredictable, spiteful, self-centered, cold, aggressive, arrogant, envious and ruthless.
Not sure about athletic or envious lol. Tbh, after reading all the traits for each personality type, I think I kind of match all of them to some degree. I don't rly believe that your blood type determines your personality but I guess it's a bit of fun.