Korey said:By target times are you referring to how much time before Doom kills you on a boss?
Star-rating on the battle completion screen. The better your star-rating the more likely you'll get a drop (if I understand this correctly). Doom usu. only comes into play if you take an excessively long time to kill a boss (although there might be at least one boss that likes to cast it when you get him under 50-30% health).