The Trapped Beast summary:

Once a prince of a fallen nation, but due to the defeat in war, he could only be reduced as a prisoner and become plaything for the powerful people of the victorious nation. Xing Mu, who endured the humiliation and disguised himself as an Omega, was on a mission of revenge and restoration of his homeland. However, his biggest obstacle was the helpless second prince of the enemy nation — a beautiful omega who was marked by him in an accident. Therefore, the love and hate between the two, accompanied by the dark surge of revenge, tightly entangled together...