Rajak is the leader of the Kertia clan, a family known for their assassination skills. He wields two daggers as his soul weapon, which are identical to those used by his younger brother Rael. However, unlike Rael, Rajak's soul weapon is incomplete due to the fact that he does not hold the position of clan leader. Despite this, Rajak possesses impressive control over his soul weapon and uses it to conceal his aura and move with great speed. He can also create multiple copies of himself to confuse his enemies. Rajak is extremely loyal to the Lord and executes any orders he receives without question. He shows respect towards other clan leaders, but scolds Rael when he disrespects Gejutel. Rajak performs his duties as a leader with great dedication. During their fight with Frankenstein, Rajak was able to wound him using a sneak attack. In response, Rajak slashed himself to compensate for Rael's actions.