Tā shì wǒ shīxiōng de túdì, yě jiùshì wǒ de shīzhí.
He is my martial brother's disciple — in other words, my martial nephew.
Tips
culture
Family metaphor inverted downward: if 师兄 is your 'martial elder brother', his disciple is your 师侄 ('martial nephew'). Common address in wuxia sects and across generations in traditional schools.
