A Dragon pearl could be said to be both fantastic and useless at the same time. That's because other than dragonkin, no other race could make use of its features. Krune, for example, would be unable to use even an iota of its power. Even for dragonkin, their Dragon Bloodline concentration has to be at least 50% or higher.
A Dragon wouldn't use it as a weapon. Instead, they would fuse it with their body, enhancing their Dragon Bloodline power. Once the battle is finished, they can then cancel the fusion, and the Dragon Pearl would come out.