Unsolved Mystery — Legends: Ødeguard Demonslayer: Chapter 4 — Continuing the Journey

As Ødeguard climbed up the mountain, an enormous cloud of smoke came into sight...a base...It was the hidden base of the barbarians who dared to attack Ødeguard’s village—Doomsday.
Ødeguard walked closer to the base, and realised, floating, translucent blue figures around the base. They were souls of the barbarian soldiers, guarding  every single inch of the perimeter. It's just impossible to get in. Thought Ødeguard, except...from above... he thought as a bird shot into the base without being shot down. Ødeguard wandered around the base's perimeter for a long time, thinking of a way to get in. Suddenly, a deafening roar filled the air as a black dragon rose into the air, then flew for Ødeguard. Ødeguard shut his eyes tight, preparing for his death as the enormous black dragon shot for him. But it never came. It landed right in front of him, and stood there, quietly. Ødeguard slowly opened his eyes, and looked straight into the dragon's eye, while reaching for its snout. The dragon lowered its head and half-bowed to Ødeguard. It was tamed. Ødeguard thought perhaps I'll call him Eragon. As he climbed up Eragon's back. "GO!" He yelled, as he pointed to the base. Eragon seemed to know exactly what he wanted to do, as he flew high up to the sky, folded his wings in, then dove for the base soundlessly...