In the Maha episode we will see that Jalandhar tells Vrinda that he won't marry until she agrees. On the other hand, Mahadev kills Dooshan and gives blessing to his Shiv bhakts. Vrinda(Neha Marda) accepts her loyalty and dedication to Jalandhar in front of Shukracharya and Vishnu's deity and thus Jalandhar is protected.
Further, we will see that Jalandhar defeats and humiliates Indra. He thinks that since he has defeated Indra, he has become the king of Triloka, failing to understand that Brahma, Vishnu and Mahesh are the only Triloka and no one can replace them. Naarad goes to greet him and points out that the supreme lord is still Mahadev.
When Jalandhar hears about Mahadev as the supreme God from Naarad, he panicks thinking no one can be supreme to him and hence he starts to think of defeating and replacing Mahadev. This will lead them to come face to face for the very first time. To know what happens ahead don't miss to watch the maha episode of Devon Ke Dev. Mahadev.