How many Pokemon trainers can appear in the Pokemon league?

Question

Sometimes when I defeat the elite four and I'm on my way to Hau, many other trainers appear I would like to know what trainers appear?

Answer 1

It is not always Hau. These trainers can also appear.

• Ryuki, who specializes in dragon types
• Plumeria, who specializes in poison types
• Hapu, who specializes in ground types
• Sophocles, who specializes in electric types
• Youngster Tristan, who has no specialty
• Guzma, who specializes in bug types
• Kukui, who has no speciality
• Gladion, who has no speciality
• Lusamine, who has no speciality. Note: Lusamine appears on the first of the month, based on your 3ds clock.

Source: https://www.serebii.net/ultrasunultramoon/elitefour.shtml