Chemestry
Don't worry - I'm not flaming the serial (not yet, anyway). And Vinu is right about Bhima being the one who killed Jarasandha, as well as Dwaraka being inaccessible to the enemies of the Yadavas.
But the 17th war was the one where Krishna & Balaram were surrounded by Jarasandha's troops on a hill, and he had a fire lit around them, and they jumped off the top. To Jarasandha & his allies, it looked like Krishna was dead, and hence the precap of Rukmi informing Rukmini of Krishna's death.
But my criticism here is mainly aimed at the characterization: w/ anybody familiar w/ kshatriya maryada - which was embodied by both Rama & Krishna, as well as other great warriors like Lakshman, Balaram, Bhima & Arjun, what Krishna did today - encourage Balaram to go & fight so that he doesn't have to - was something few kshatriyas would even dream of doing. Such a characterization really serves him poorly, when it's well know how much pride kshatriyas - particularly in that era - had in their valor.
I really hope the CVs do a proper introspection of Krishna's character b4 butchering it any further.