A couple seasons ago, back before Kelly was born and Diana was still all mysterious and a grave threat if she were to turn dark side, I thought they could have made a spin off with Kelly (years later). He'd be a special Grimm (when things got really tough he'd woge like Renard plus he'd inherit the zombie trait) and his main nemesis could have been eventually been Diana (assuming she went bad).
When I first saw the 20 year flashfoward and they showed an actor playing Kelly, for a brief second I had a glimmer of hope that we were seeing the beginning of real spin-off they had been able to keep secret. But then Diana walked in and Kelly grabs the staff and that glimmer of hope died right there. You can't make a show from that. As others have said, Diana is way too powerful just on her own, and there's also Kelly (Grimm + Zauberbiest with all powerful staff) and the others that were mentioned (triplets, mom and dad). Total yawn fest, nothing in the Grimm universe could stop them I think.
When I first saw the 20 year flashfoward and they showed an actor playing Kelly, for a brief second I had a glimmer of hope that we were seeing the beginning of real spin-off they had been able to keep secret. But then Diana walked in and Kelly grabs the staff and that glimmer of hope died right there. You can't make a show from that. As others have said, Diana is way too powerful just on her own, and there's also Kelly (Grimm + Zauberbiest with all powerful staff) and the others that were mentioned (triplets, mom and dad). Total yawn fest, nothing in the Grimm universe could stop them I think.