>>38159646It would depend on the individual, but I imagine most Leafeon would probably like Vaporeon, because plants like water. That said, I bet most Pokemon would feel nervous around any types they're weak to, so Vaporeon might not like Leafeon back. That may extend to the other Eeveelutions too: Glaceon generally wouldn't like Flareon, Umbreon typically wouldn't like Sylveon, etc.
