What Nature is better for Lucario, Lonely OR Adamant?

Question

I have choosen this 2 natures because they boost attack of Lucario, in my opinion I really think is Adamant because most of Lucario's attacks are physical and less special so Adamannt wins?

Comments

Depends very much on the moves. Special Lucario is perfectly fine in most cases where physical Lucario is good. Lucario's most needed stat is speed, so the best nature would be either jolly or timid.

Answer 1

Well from the choice of Lonely or Adamant, I'd say Adamant. I'm pretty sure that one's the better choice out of the two.

Answer 2

Lonely
While Lucario may have a larger physical movepool. It also has access to useful special moves, making it a very versatile Pokémon. It's defense, however is nothing short of useless, especially with Close Combat.
Lucario has higher special attack than attack, but barely, and a Mega Lucario has a slightly higher attack stat. But it would be a shame to just ignore the special attack. If you have to choose an attack boosting stat, go with Lonely. But on a Mega Lucario with Adaptability, you should have a speed boosting nature, like Hasty or Naive.