I have done miraculous ladybug react to their other self from another universe so why not do httyd but after homecoming where Zephyr and Nuffink learned about the dragons so they reacting to their past.
I pushed a button on my remote to bring up the chairs, food, toiles and the top floor for the dragons with different types of fish.
I pushed another button on my remote and it sent a bright light out into the viking world where it swept all over new berk, hidden world and the outcasts, berserker's, defenders of the wing and the wing maidens.
On the left side will be where new berk will be while on the right side everyone else.
Welcome Vikings you'll be watching the past. You'll be watching the end of the dragon wars
So sit back and relax.