Injustice 2 Storyline ()

"Can't fight crime without cracking a few skulls."
Storyline of Red Hood
Jason Todd once served as Batman’s second protégé "Robin" before being brutally murdered by The Joker. Years later, the powerful healing waters of the Lazarus Pit brought Jason Todd back to life. However the power of the pit comes at a cost, and a change takes hold in Jason. He now uses mantle of the Red Hood to wage a lethal war on crime.
Batman is Red Hood's foster father

The Joker killed Red Hood