The Kertia Clan specializes in speed, stealth and pathfinding: they have the unique ability of leaving undetectable traces which can be read only by another member of the Kertia clan. During battles, they are said to be so fast that their opponents do not even learn of their death until they die. They can move at great speeds to create doppelgangers of themselves, all of them able to attack the opponent although they are partially illusions. They can also dissolve into the surroundings and kill the opponent at ease, leaving them clueless.
Because Kertia Clan's greatest attribute is speed, their enemies have great difficulties fighting them. Even if enemies win, they are unlikely to come out unscathed.
Although the family bonds between clan members are strong, it is especially stronger with Kertia clan; Ragar went into a great length to split his soul weapon into two because he felt he couldn't leave Rael with nothing, even though he knew his decision would leave Rajak incomplete as a clan leader. As for Rajak, he was willing to relinquish his clan leader title whenever Rael really desired but Rael, out of respect for brother Rajak, declined. Rael later confessed that he wanted neither a complete soul weapon nor clan leader title at the expense of Rajak's life. Upon learning Rajak's demise, Rael immediately vowed vengeance upon not only those who killed him but to everything and everyone that has to do with Rajak's murderers.