>>20961664Well since you were under leveled to the elite 4
even though you fought every trainer, it must mean
that you are spreading the exp out really thin.
I also have a pokemon that is always a few levels
higher than the rest, but it's not something I do
on purpose, for me it has to do with what type
of gym I fight, for example gen 1 the last gym
was ground, so I just put Blastiose as lead and
only used him to power my way through the
gym, meaning he got all the exp and went a
few levels higher.
Exp share in XY gives the same amount of exp
and EV's to the whole party, so the exp will
never be spread out to thin because everyone
gets it, so you don't have to prioritize who will
get the exp from what ever you are battling. So
in XY not having a party of 6 means you are
actually wasting exp that could have gone to
some other pokemon.
Sorry for wall of text.