The protagonist switches to Xuanxin in Emerald Town. Find the old man in the west of the city to answer the question and you will get the Phantom Beast Summoning Ticket (there are 4 other identical ones. After you find them all, you can get a powerful Phantom Beast by looking for him). After you get the Unicorn Hound in the shopping street, you can get good rewards by calling others. 
Go to the east suburb of the city 2 and see a monster attacking two children. After destroying the monster, you learn that a demon has appeared in Morning Light Town. From the eastern suburbs of the city, walk straight up to Chenguang Town. You will meet the Old Man of the Wind on the road, and you will get some good things by answering his questions. The Mushu Dragon next to him can be challenged repeatedly. 
Meng Yu and others are fighting the devil. At this time, you can freely switch between the two protagonists to fight. It is recommended to upgrade Mengyu's fantasy beast to level 10 or above first. After helping everyone in the town escape, Mengyu will tell Xuanxin about the origin of the devil, and the two decide to go to the guild in Green Mountain City to find Master Qin Ming. You can reach Green Mountain Town by walking eastward from the eastern suburbs of Jade. 
There is a cave in Green Valley. It is recommended to challenge it after level 30. The monsters inside are very powerful. You can try to steal a few with summoning tickets. 
After returning to the guild, Julie will tell the protagonist Qin Ming to investigate a ruins in the south and may be in danger. Go south from the exit below Green Mountain Town and you will find 1 ruins. After entering the ruins, take the teleport on the far right to enter the 2nd floor of the ruins. Use the teleport in the middle of the 2nd floor to reach the different space and find the fantasy beast Suzaku. She will give you the skill to summon Suzaku. Continue to move forward to find Qin Ming and the fantasy beast Tie Xuan. I learned that using the Reincarnation Stone can unlock the fighting abilities of Tie Xuan and Suzaku. 
Returning to the guild, Meng Yuhui received the task of investigating the disappearance of Phoenix Town. He returned to the shopping street of Jade Town and headed south to Phoenix Town, where strange things happened. . . (to be continued)