So my Vildred is level 32, and since I’m fairly new I haven’t really built him up much, my team is Aither Dizzy Rose and Vildred atm. I’m only asking this question since I was told to do Wyvern.
Build Vildred first. Once you have Vildred on ok gear levelling up other characters will be very fast, because Vildred is one of the best AOE dps.
You can switch the gear to Karin once you finish the story maps and start farming wyvern.