I have several questions for Pokemon Diamond nintendo Ds. So I'll just list them.

Question #1: In the pokemon Day Care center, as well all know, pokemon level up after a while in the Day care center. I'm trying to find out how? Do pokemon level up over time or by a certain number of steps your character walks?

Question #2: I finally made it to the pokemon league. I have diagla level 50 and empoleon level 60. What type of pokemon does the elite four have and what type of pokemon should i use? fire, water, Etc.

Question #3: Where do I find ethers? My pokemon's attacks have around 30 pp or below and I have no ethers at all. Where do I get a high number of them? I tried every pokemon mart
( shop ) but they don't sell any!

Thanks for listening and I hope you have answers to at least one of these questions. Thanks!