Descendants of Blood

Two millennia ago, the gates of the underworld were opened. Demonic beings who thirst for human blood roamed the earth and wreaked havoc on humanity infecting them into blood thirsty undead beasts.
The world was thrown into chaos and humans were at the brink of extinction. Malachi, an angel sent to protect mankind did all he can to drive the demons back to the underworld with the help of the humans. In the end, he failed to drive the beasts and sacrificed himself, transferring his powers into four powerful stones. The four humans who led the survivors of the onslaught used the power of the stones and in one final battle drove most of the demons back to the underworld and freed the souls of the infected humans. This was known in history as the Great Blood War. When the war was over, the humans, keeping a part of the power within them hid the stones with their magic, only to be opened when humanity has need of them again.
In 2015, the written history of the demons and the war were lost in time. At this modern age, humanity have discovered a technological breakthrough. They invented the first machine capable of travelling to a different realm. This turned out to be their biggest mistake as it opened a portal to a time before the Great Blood War and where demons roam the earth freely. Before they could understand what was happening, demons have gone through and history will repeat itself leading to the complete extinction of the human race.
Four unlikely survivors must uncover their true bloodline and will travel back through time to stop the demons and lead humanity in their fight for survival.