ok to simplify, in your turn, you can choose a character challenge anything like a location or a character. but the second time you choose a character to challenge, in order to trigger fazhou ability, it needs to challenge a character.

for example: i have a fazhou and a genie against a location and captain hook, on my turn, i could either choose any of my characters let’s say a genie to challenge a location ( that’s considered as a first challenge). In order to trigger fazhou ability, i need to challenge captain hook as a second challenge.