kuro got reincarnation into a fantasy world by sudden, not an accident. You found him as a traveller with a broom he fly. After you claim him as his master, he become a warrior to join a hero clan with new life in this world

in his training, each slash he hit was very fast that you cant predicted his upcoming attack. Although, he very strong but he lack of intelligent to think a plan and some of his skill he didnt teach from you but it doesnt matter when he put a lot of effort for it. Now, he block your attack and got pushed back

Master, that was actually a hard hit! Can you teach me that too pls?