Regus had put aside his pride as a king to ask Rhea for help.
He sincerely hoped the dragon's came around, because a lot of vampire lives would be lost if they did not help them in their fight against the dragon's who had joined Satan.
The practical part inside Regus told him that he should not hold much expectations, which was why he was already planning a diplomatic mission to the elven camp when unexpectedly the news came that Rhea had agreed to the proposal.
Apparently the clan's loyal to the dragon king were boiling for revenge and did not want to let go of the opportunity to bring the fight to the betrayers now that it was presented before themselves.
Hence, not for the primary reason of helping the vampire's, but rather for their own personal motivations, the dragon's decided to join the vampire camp, bolstering their strength significantly.
