I’m searching for a good ralts but I’m thinking about nature does anyone have a suggestion?
If you want the Gardevoir to hit hard I would give it a modest nature, this will increase special attack, and decrease attack, though this attack decrease doesn't affect Gardevoir as it doesn't learn any good physical moves.
Timid or Modest, depends on what you want. More special attack is nice for an in-game Pokémon, but for competitive you'll almost always want to go with Timid to outspeed as much as possible.