Paradox blue manga

Paradox Blue summary:

*previous named as Angels Falling Down. "What is the boundary between game and reality". The world is in danger. Strange juggernauts called "Angels" have started to appear all around the planet, presenting riddles called "Angel Paradox" to whoever happens to be in the near vicinity. Answer right and your land will receive God's blessing. However, fail to solve the paradox and the whole place will be literaly nuked with divine punishment...