A Pawn in the Early Tang Dynasty

Am I the villain at the beginning? Impossible? Here is Li Shimin, the first emperor of the ages, and Prince Li Jiancheng. There are also many dazzling civil servants and generals. I neither belong to Li Shimin nor Li Jiancheng, but I belong to the Tang Dynasty that is against them? What kind of trouble is this? Did he just travel back in time and be artificially transported back? But no matter what, now that we have come to this magnificent Tang Dynasty and are about to witness the rise of an eternal emperor, no matter what, we must be a trend-setter in this era of great changes, rather than a villain who allows people to be flesh-and-blood. The protagonist just thought this, left the camp that was against the Tang Dynasty, and joined the Tang Dynasty, a big family destined for justice, but you asked me to be the guard of Xuanwu Gate? What's going on? The current emperor is still Li Yuan, and the Xuanwu Sect will happen soon. I'm still in Li Jiancheng's camp. Am I a destined villain? Impossible, I am a good person, a truly good person.