Basically its not the most creative but um... Daniel d*es from the P*isoned Cool-Aid (yeah...they made that ref if u get it) and decides to possess David to continue his 'religious' acts ((If u dont know who daniel is, he is basically a recolor of David (on purpose since he is basically David but insane and highly religous and is based on a actual group event that was horrible and crazy) he appears in episode 1 of season 2))