Spoiler warning: Plot and/or ending details follow.
Khel is a humble commoner Klingon who despises the ruling class which treat those of lesser station poorly.
His family is of the cast of craftsmen, from which he learns from his father.
In addition to his cast training as a craftsman, he is skilled in hand-to-hand combat; he is the best fighter of the group of the servant descendants so it is he who trains T'Kuvma to fight.
After J'Ula becomes engaged, he leads the efforts to restore the 'ship of the dead' back to it's former glory.
Many years later he warns T'Kuvma of the change exhibited in his sister and asks that T'Kuvma not attend the feast in sister's honor; T'Kuvma attends anyhow and this leads to the discovery of betrayal and the a new direction in life for T'Kuvma.
Years later after searching far and wide for the beacon Khel shows his lord T'Kuvma the fruits of many years of his expert craftsmanship.
Khel crafted the beacon which T'Kuvma lies to his followers telling them that he found the long-lost beacon of Kahless. The lie was not important for Khel explains that T'Kuvma was the true beacon for his people, to lead them to a better future. (DSC - The Light of Kahless comics: "Issue 1", "Issue 2", "Issue 3", "Issue 4")