Both of the dramas are suspense and have detective elements in it. Also, the main actor - Ikuta Toma. Maou has more emotional intensity and Majo Saiban has more intensity in terms of "I have no idea what's happening here".
Both have similar filming style and visualization techniques. Both present a group of people randomly brought together and forced to play a game with their lives at stake. Greater powers operate behind the scenes.
There is the same atmosphere like in Bloody Monday, there is an incredible suspense which plays with spectators on their attention and ability to predict next step.