I am doing A Ripple in time and I already have an Espeon. Is there a way to complete the research of evolving Eevee to Espeon?
No if you got your espeon before you started that quest it doesn’t count you have to walk eevee for 10k and then evolve it in the day (you cannot catch it wild or use sakura trick for this quest)
Remember: HAVE EEVEE AS YOUR BUDDY WHEN EVOLVING!
Have an Eevee as a Buddy, walk it 10KM to earn 2 candies, then evolve it during day time while it is still your buddy. I believe that’s the only way to complete the task.
I believe the quest even tells you how to do the 10km buddy and evolve during day trick