One of the central themes in Supernatural is the bonds of family, and its strength to overcomes any obstacle that comes before it. The Winchesters and thier brotherly love were a testament to this when all seemed lost they chose family overall and won the freedom destiny denied them. Carrying Sam out of their burning house when they were children set into motion a chain of events involving an impala, one old drunk, and a fallen angel fighting for an ideal that peace and freedom aren’t the same though both are worth dying for not matter the cost.The choice Cas made to help Sam and Dean fight against the apocalypse re-enforced a shared understanding of his universe were family and loyalty trumpets orders formed out of righteous beliefs. Letting even the most ancients and powerful beings like God and Death to support there attempt to stop the apocalypse by resurrecting them numerous times. Strengthening the idea of family above all else finally evident by other characters like Ellen and Joes choice to die together granting enough time for the Winchesters along over scheduled meeting with evil himself. Even Cas treats the other angels as cherished family no matter what rank they are or if ill intent only wanted towards him. Between Michael and the other four archangels, order falling into chaos because of team free respect and family values fell apart in the aftermaths. Best representation of unity through blood in supernatural is Cas vessels family who despite being torn apart by angels, demons, by destiny itself a memory a what they were keeps them going until they meet again in heaven. Finally, the central story of two brothers who flew opened armed into the skies of truth and liberation, tarring up scripts scrolled down by fate derived from plan’s seen ages in advanced.