If there are other booster, Priests,Armmeggadon and Drakkus what made Dragonbooster more special.So far he gets his ass kicked by moordryd ,Drakkus and Armmeggadon?

I think DB is more powerful, but he hasn't shown it yet, which is why he gets his butt kicked. Artha still hasn't learned how to release the full power of the dragon, he's still training. Because in Professor Stubborn, Parm says they have to find more pages of the Magna Draconis so Artha can understand the nature of how to release the full power of the dragon. He's special, but can't unleash his specialness yet.

Yeah i agree, he is getting his but kiked but sometimes he does the kicking, moodryd beats him sometimes because he is been trained by a warrior from the first original dragon human war, so moodryd has the upperhand, and armaggedon is way more experienced than artha right know, but artha will get better and do more butt kicking

yep that pretty much sums it up :)

Yes, Artha and Beau are potentially powerful, but not yet. Mortis said explicitly in the early episodes that Artha has to train to learn how to release all of Beau's powers. This is the scripted story rationale for why Artha has to learn to race (that and for income during his missing dad days).

An interesting side question is if Beau knows what all his powers really are or if he's figuring it out as he goes along too. Like when he jumped off the ledge in episode 2, did he know he could sprout wings and fly? Or was he just a lucky dragon? :D

Perhaps as he had the bone mark of the original Beau, it tell it sometimes what to do