Hi, I've decided to start a fanfiction and was going to post it here, but unfortunately, I don't think there will be enough space to put the entire thing.
It will contain all main DN characters, and I'll just post the summary/link if you're interested :)

As L continues his constant battle against Kira, an old acquaintance seemingly rises from the dead. The detective must now face not only one, but two mass murderers. And if that wasn't bad, apparently B isn't as forgiving for the institution in which he was raised. Sinister plans door meer than one have been made. No one is veilig any more, and no one can be trusted.

link