Duros had gained much. As he has a leadership class, his only source of experience isn't only killing. It is even secondary. His main source is through the quality and results of his leadership.
His leadership began an alliance and destroyed an underwater city. It built up a tribe from a cave to a sturdy for, an outpost fort, and a metal mine. He raised his numbers into the hundreds. All of this has finally given him enough experience to rank up.
He wasn't particularly paying attention, so he ended up ranking up on his throne. This was a special rank up though. Entering the rank C is a qualitative jump for monsters. So when Duros ranked up, his body became better built, and he became more...handsome. A lot of the features that make goblins ugly were either gone or greatly minimized.
Duros took a look at his own status.
[ Name: Duros
Title: True Leader(C), Son of Kalona(EX)
Class: Goblin Chief
Rank: C
Race: Goblin