Soul attack is something new for Argholas. He never heard or even think that such attack exist. One of them of course because he never really looking for it, but another bigger reason is because he never really need any other kind of attack.
His claw, fist, kick, bite and magic always serve him well and give him easy victory. Sometimes it becomes too easy that Argholas have to fake weakness or play easy on his enemy just to get a proper fighting experience.
But always being the strongest also make him complacent and become a bad habit for him. He become less likely to be serious in battle and always unconsciously weaken his attack and defense from time to time.
This issue is something that Argholas trying to fix in the battle against the nine dungeon master. These nine have a perfect coordination and have the capabilities to combine their moves. They also able to adapt to any formation among themselves without any delay.