[RandomAvatarFan]

What do you mean "focuses on the mystery"? Any of the Chiru arcs "focus on the mystery" because they're about 75% meta-discussions about the logic and mystery. If that's the case, the formula I'm using is the regular formula where once the bodies are found Battler and Beato (or whoever your Meta Characters are)spar for a bit, and then have the red/blue battle like the end of EP4 and EP5. You can throw Dlanor and Erika in too to keep the discussion intense.

Or do you mean something that has very little fantasy à la EP1 where the magical entourage is all but seen, more like a traditional mystery? (EP1 is revealed to have many "fantasy"scenes though as well, so it might not be your best example) I'm terrible at writing those. For that, make sure you know the rules of the board exactly, and work at it in a similar fashion of EP1 where you don't know who died until the bodies are found. For instance, if your story is being told through Battler's eyes, he's not usually going to attend the parent's conference, so instead of saying what is going on in the conference, you tell what Battler sees in the cousin's room. Next day, six of the people who were in the mansion were killed. While it is possible for Battler to lock everyone in one room and still have bodies piling up, it's easiest to split people up.