The immediate threat on Lucius' life is minimal, however, they will most likely force him to use his bloodline abilities. Using these spells too often would impact his lifespan and talent causing him to slowly wither away. As a magic beast, his lifespan was extremely long so the process would be gradual death so he could nevertheless be exhausted enough times by whoever manipulates him. The constant exhaustion would also prevent Lucius from advancing in power, so he would not obtain the chance to revolt. All these scenarios were described to him by Lucius during their times together. Although he tried to act unfazed by the possibilities, Lucius let out signs of a deep-seated fear of being confined.