You can breed Lucario with Ditto or trade for more, but you can't actually catch any more.
Yes, because it is more powerful when it evolves into a Lucario than just staying a Riolu.
kangaskhan a good website to find out about Pokemon is http://Pokemon.marriland.com/diamond_pearl/pokedex/list/all/ ^ copy and paste it to the address unless it has a hyperlink in normal dex its riolu
Riolu is one of the more difficult Pokemon to find, you have to place specific items in the mountain zone and wait over a period of three weeks. The easier way to get a Riolu is to purchase a copy of Diamond, Pearl or Platinum (or get a Friend with a copy of one of these games) Trade over a Riolu, problem solved
Riolu doesnt technically have a point where it evolves. It evolves based on happiness, just like a chansey. The more you use it in battles and what not, the more happiness it gets :) ( I suggest going on cycling road and fighting people there with it )
Run around more with it, as you walk while Riolu is in your party, it will grow happier.
Be more specific please.
Yes and No they are in Diamond but they are more common in Pearl but luckily for you yclaw fossils are more common in Diamond then Pearl! But try your best to find both!
in diamond you can give them a certain berry and they will like you more (that is, if you can find the berry).
No you can not have more than one login in Pokemon diamond.
You have to have the national pokedex, because you cant find a lot more Pokemon without it. :)
It amplifies type effectiveness for that pokemon. So a Riolu with Erratic Player will do more damage with a Fighting move against a Normal pokemon, than another Fighting pokemon would with the same stats. But that Riolu would also take more damage from a Psychic move.
By Pokemon 69, do you mean #69? If you are trying to catch it you can find it in the Lost Tower if you just need to see it look on serebii.net to find out more. Pokemon 69=gastly