Complex sentence: He successfully learns both of this techniques and becomes so adept at using the "Hadome", that Yahiko starts performing variations of the technique, even becoming famous when he is a teenager due to his title of "the man who has caught 1000 blades".
Split into simpler sentences: He successfully learns both of this techniques and becomes so adept at using the "Hadome", that Yahiko starts performing variations of the technique. By the time he is a teenager he even becoming famous due to his title of "the man who has caught 1000 blades".