Question: how to unlock ssj4 in xenoverse 2?
Answer: Complete Parallel Quest 93 to unlock Super Saiyan 4 Goku and Vegetta. You get both of them by beating this quest and the name of this quest is “Small But Strong!”. You need to complete the quest in order to unlock this parallel quest. You'll get Super Saiyan 4 Gogeta only after completing Quest 94.