This is how Epilogue: Deker's intro goes in The Impending Duel.
[Then we see a shadow figure coming out of the woods as it reveals to be Deker]
Deker: So, my cursed opponent has defeated the dinosaur warlord. Impressive.
[Then Deker goes to Sanzu River and finds Master Xandred]
[Deker speaks to Xandred]
Deker: Master Xandred, I have news for you. Mac is still alive and on the Isle of Berk with his friends.
Master Xandred: What? Mac still lives? What a headache.
[Octoroo and Dayu learn of this]
[Octoroo realizes something]
Octoroo: Ooh-ah-ooh, Mac still has the sealing power which is capable of sealing us to the Netherworld forever.
Dayu: How did Mesogog know it and you didn't?
Deker: No matter. With him out of the way, this is the perfect opportunity to duel Mac without interference.
[Master Xandred cackles as the film ends]