a few questions

1) Riolu can only evolve when it has very high Happiness and it is leveled up, with it's high Happiness, in the Day.

2) You can make poffins, in the little house in Hearthome City. It is located directly right of the Church.

3) Actually, you can't catch Palkia in Diamond, but you can see it by going back to Celestic Town, to Cynthia's Grandmother, who can be found in the biggest House, in the Northern Part of Celestic Town, but you can only do this after you have battled/caught Dialga. You could obtain Palkia, however, by trade, after you have received the National Pokedex.

4) To get Darkrai, you must first get the Member's Card from either a Nintendo Event or by the Mystery Gift. Next, you must go to Canalave City, to the old hotel, which is the small building in the very Northeastern corner of Canalave City. Use the Member's Card to open the door, then go in. Next, the man inside will offer you to sleep, and except his offer. You will be in your dreams, on New Moon Island. Next, make your way up the Island. At the very end of the Island, Darkrai will be waiting. You will then be able to face Darkrai.

5) You can obtain HM Defog, from the first person to your right, in the Safari Game, which can be found in the Northern Part of Pastoria City.

6) You can receive TM70 or TM Flash, from the the Market Ladies, on the Third Floor of the Veilstone City Department Store.

Hope this helps you!!!

1) Get it at Max Friendship.

2) In Hearthome City. There is a house that I think is next to the Poke Mart and it has a sign in front of it that says "Poffin House.

3) Darkrai- You need either an AR or a Nintendo Event item called Membership Card. When you have one go to Canalave city and go to the locked building and then you can go in. The old man says he has held your reservation for 50 years. He will give you a boat pass (I think). Thhen go to the boat guy and he will take you to New Moon Island. Darkrai is there.

Palkia- You can't catch Palkia in Diamond. But you can get it from the GTS or from a friend.

3) Defog- Go to the Marsh Zone and talk to the first guy on the right.

Flash is not a HM. Nintendo changed it to a TM. You can buy it in the Dept. Store.

1. Get the Riolu to max happiness. Then it will evolve.

2. In Hearthome City there is a house located right next door to the Pokemon centre. Go in and you can make them there.

3. Darkrai- You need to get it from someone else, or with an Action Replay. The event that allows you to get him has passed and you cannot get it that way anymore.

Palkia- You cannot catch Palkia in Diamond version, you have to get it in Pearl.

3. To get defog, go to the Marsh. Pay the money to get in, and as soon as your in, talk to the guy with green hair to the right of the door.

Flash is a TM in this game. You can buy it at the Department store.

I'm not sure about the last 2 questions but Roilu evolve when you have enough freadship and you may puffins in Hearthome City.

Or 4 PALKIA you can use Pokemon modifier cheat.And you could use run/walk anywhere cheat at fullmoon island at the right keep goin till newmoon island.poffin house in Hearthome.And RIOLU friendship in day.Or 4 PALKIA see the thing n Celestic town.DARKRIE also member card.Here is a secret at where you get DARKRIE use run/walk anywhere cheat go past where DARKRIE is and you walk on the thing sideways.Please rate my answer.