I've been wondering this for a little while, but seeing as the Otherworld Series is in the same world and theme as The Darkest Powers and Darkness Rising stories, is there a chance that characters from Otherworld may appear in the adventures of Chloe and M

It’s possible, but I’ve run into timeline issues. The Rising is set in 2008. 13 was set in 2009. But the latest Pack novella I wrote is 2012 & there’s no mention of Derek. There can’t be, because he’d be 20, and if I had him in that story at 20, the YA readers would be horrified—what happened to the last four years!!