The Thunder Dragon is not terrifying.
The Thunder Dragon is just a small classification within the True Dragon race; True Dragons are still common on the Primordial Continent, and it's not to say they are particularly powerful.
But this Thunder Dragon, its bloodline concentration has reached five percent pureblood. That's frightening!
Generally speaking, once the bloodline concentration awakens, it's considered as someone within the race.
For example, if you possess even one percent pureblood of a True Dragon, you are basically an awakened True Dragon, not a Mixed Dragon, which has absolutely no pureblood at all. That's why it's called a Mixed Dragon. But having even one percent pureblood means you're a dignified True Dragon.
But in this era, at least on the Primordial Continent, over half of those True Dragons have awakened only one or two percent pureblood, and even three percent pureblood is rare.
And this Thunder Dragon that Su Chen has encountered!!!