How do i level up a Pokemon VERY fast?

Feed it rare candies.

>>31217176
Just inject lol

Play gen 6.

Lucky egg, traded Mon, xp opower.

Lucky Egg + an elite four run can usually get them to about level 40 in about 15 minutes.
Festival Plaza apparently has good stuff if you've grinded enough for some good stores/enough coins.
I think feeding them Poké Beans increases their exp. yield

>>31217215
>I think feeding them Poké Beans increases their exp. yield

Yeah, one rainbow bean should be enough for that

>>31217215
Yup, you can raise its affection in Refresh to 3 hearts to get a .5 boost in exp, stackable with Lucky egg. Also if you're going to sleep you can put a batch of pokemon in the pelago with lots of beans.

>>31217176
with battles

>>31217254
The pelago exp gain is retardedly slow, however.

Blissey bases in ORAS were the best way ever.

Press F for pay respect

diaper beam lol