The strength and power of demons are based on their level of evolution. That's why they are demarcated into ranks. Even their stats are demarcated into ranks too. The ranks for stats range from Fragmented, low, middle, high, pinnacle, extreme, and so on. These correspond to fledgling, low, mid, high, demon noble, demon lord, and so on.
He laughed a little when he saw his title. He had two titles which no legion has. The other clones of legion can't share in his title because that would mean he has to channel pure Chao energy through his soul into the soul artifact that bonds them. It is not a risk that Legion is willing to take.