Twins

Double trouble, indeed. These guys are Fei and Hung, named after the famous martial artist Wong Fei Hung. Li encounters one of them in 'Take Out Order' and both of them in 'Lethal Lounge', right before the final battle against Kwan. The player is advised to not even attempt to identify them because, unlike other twin video game characters who usually, if not always, have something to help players in telling them apart, these two are exactly the same in every possible aspect.

While the battle is unfair, it is not that difficult. Just focus on one twin while dodging the attacks of the other because they can perform a tandem similar to that in the Double Dragon and this is the tricky part. Stun them in order to launch a massive combo on them and take as much advantage as you can while they are attempting to recover. The battle becomes a lot easier after you eliminate one; the other isn't much without his brother. Rinse and repeat.

The twins fall to their deaths from the tower's balcony in the cutscene after you defeat them. It's a long drop and certainly not a pleasant one.

Console Strategy
These two bad guys are agile, have jump attacks and can use each other as weapons. Don't try and tackle them head on, as they will backflip to avoid their attacks. Mostly, use your blocks and counterattacks to damage them or allow them to hurt each other. If one or both twins get groggy, immeadiately attack either one of them. Repeat these strategies and they will be defeated.

Trivia

 * The twins are named Fei and Hung, a reference to the historical character, Wong Fei-Hung in the Once Upon a Time in China series. Also, Jet Li plays Wong Fei-Hung.
 * They're the only recurring bosses in the whole game.
 * The twin boss fight before fighting Kwan is a reference to Kiss of the Dragon, another movie Jet Li starred in.