View gallery Kylie Jenner testified within the $100 million defamation trial between Blac Chyna and the KarJenners on Monday April 25. The 24-year-old Kylie Cosmetics founder claimed that her ex-boyfriend Tyga, 32, had advised her that Chyna, 33, had slashed him leaving a scar, in accordance with TMZ. Extra Associated Information: Tyga and Chyna dated from 2011