In another major shake-up for the DC Studios, Skydance is replacing Hollywood director James Gunn and producer Peter Safran with a former Marvel executive. Skydance Motion Picture Group announced Monday that James Gunn and Peter Safran are stepping down as co-chief executives after four years leading DC. DC Studios leaders James Gunn and Peter Safran are leaving Skydance after four years as part of a broader executive shake-up.