After arriving at the outskirt of the Eternal Tundra, I saw a mechanical frost dragon just circling the entire Ark around over and over again at quite the high speed. So, if I want to enter the barrier of the Eternal Tundra, I have to actually fight the dragon. I cannot just went in at a timing because the speed of the Dragon is too high for that move.
Since that is out of the option, the only option for us to be able to enter the Eternal Tundra is to fight the Dragon. And then, fight the guard and force our way into the Eternal Tundra...
"Well, I am planning to fight the guard anyway... But the Dragon? This Mecha Frost Dragon... I don't have a plan to fight it... Rather, why in the world do they have a dragon roaming the entire ark anyway?"