In order to get this trophy you need to complete a stage with the five new characters in Xtreme Legends.
The five characters are:
Yu Jin (Wei)
Zhu Ran (Wu)
Fa Zheng (Shu)
Chen Gong (Other)
Lu Lingqi (Other)
If you have collected them in Ambition mode the quickest way to do this would be to do Materials stages on Beginner as these are very short and very easy.
This can also be unlocked using free mode stages if not.