Anime News NetworkI just read this up to the latest chapter (49), and find it quite an interesting premise. 12 people, each with their own motivations, were given the power of prophecy and have to kill each other in a competition to become God. Although the plot could be improved a lot more to be more logical (characters' actions/reactions in fights), it's pretty nice overall.
The manga is currently near ending with last three standing and some twists. There are another two side stories, Mirai Nikki: Mosaic and Mirai Nikki: Paradox, which I haven't read yet.
The main female character, Gasai Yuno, is probably the best example of yandere. XD