If your going to face alder, then somewhere in the high 80's, if you're going to face N, then in the high 50's low 60's.
starter lv.60
When you finally manage to fight him, his Pokemon will be levels 75 to level 77. But after beating the elite for twice to get to him you should be fine.
mostly legendary and your first pokemon you started out with but if you dont have legendaries , use high level pokemon -50 through 100-
At least level 40, it should be possible with correct type matching and lots of revives/full revives/full restores.
Nimbasa city sports Dome:Small/Big Court. Keep Challenging the Elite 4 to get the REALLY good exp if you can't win the first time.
Well, tht depends on what level your pokemon are and what pokemon you have. All i have to say is that 1. Make sure your pokemon are above level 55 when they battle the Elite Four AND 2. Dont battle with starter Pokemon
The elite fours Pokemon are all lvl 50ish so have a good team at about lvl55+ and you should be okay I recommend taking a dark Pokemon because it will be super effective against two of them the elite four are types are, ghost phychic dark and fighting you can fight them in any order you want
If you defeat the Elite Four Twice, you will have the opportunity to battle the Champion, Alder. He has mostly Level 72 to Level 75 Pokemon.
black city or white forest
i wouldn't say so as the elite 4 Pokemon have level 71
he/her should evolve at level 33
Use a Sawsbuck, Krookidile, Samurott, Vanilluxe, Unfezant, and Darmanitan. They should all be at least level 42. I beat them with that team.