At first, Kirus was shown to be a relaxed person, but it was then shown that he can be a cold-blooded killer. He admires his master and even paid his respects to him one last time, to tell him that he was leaving him and traveling the world, but even then he would not help him fight his adversary, Ares.
Under the apprenticeship of the Red-Eyed Swordsman should make him a competent warrior, but by being the number one disciple of Kirberos, Kirus is automatically a powerful fighter. He fights using a sword and is very skilled using it.
Kirus is such a skilled swordsman that he can take on multiple fighters by himself even when they are his fellow disciples of the Red-Eyed Swordsman. He is even seen toying with them, even when they are strong opponents, such as the number two disciple, Lucid.
It is seen that Kirus can have a high tolerance for pain as he was rammed into a wall and came out of it mentally unfazed. His other notable skills was that he can jump very high and can do flips to land and appear behind his opponents.