UFC 321 Countdown takes an inside look at the promotion’s return to Abu Dhabi, where  Virna Jandiroba takes on  Mackenzie Dern for the vacant strawweight title. Jandiroba (22-3) enters the title bout riding a five-fight winning streak and is the top ranked contender in the division. Dern (15-5) is coming off back-to-back wins and is ranked No.