Your competitive rival - Calem or Serena, depending on your chosen gender, can be found in Kiloude City after accepting at least one match in Battle Maison. You can battle him/her once each day- their team doesn't change with each rematch, but the experience and cash reward is very good.
Shauna, the weakest rival, can be found in Veneville Town. You'll receive a starter Pokémon from her, dependent on which of the three you chose at the beginning.
Tierno, the guy who prefers to study Pokémon's movements and often talks about dancing, can be found in Coumarine City. He'll ask each day to see a specific move.
Trevor, the shy guy, can be found in Geosenge Town post-game. He'll tell you about the Pokémon who can use Mega Evolution.
in what game of Pokemon
FAP
You find him in meteor cave after beating the elite four.
Beat them and the champion
hacks. and pokemon that are able to evolve with the dusk stone won't until you get the new pokedex (after beating the elite four)
Prof oak after beating the elite four.
At 'N's Castle after beating the Elite Four.
by beating the Elite four. no i TRIED THAT ass
Yes.
You can go there after beating the elite four.
pickachoo
Typically, Pokemon Liquid Crystal should not freeze after beating the Elite Four. You may need to restart your system before you fight them next time.