Continuously battle all the high leveled trainers: -Elite Four & Champion
-Cynthia
-Trainers in Black City
-Trainers in the two sports arenas.
OR you can get multiple 7-straight win streak in the battle subway and speak to a man in anville town who should reward you with rare candies...
Zekrom level 100 Arceus level 100 Kyurem level 100. Transfer Giratina level 100 dialga level 100 azelf level 100
You can't find any level 100 Pokemon in any Pokemon games without hacking.
No
keep battling untill the pokemon reaches lv 100
Arceus
I have a stoutland and its my favorite non legendary Pokemon but Reshiram and Zekrom both are the strongest Pokemon on black and white. This is the link to see the srongest and fastest ETC.
lv 100
At the Pokemon league.
From Reshiram at level 100.
no. with a liberty pass, you get victini, level 15
Arceus or rayquaza
Arceus the alpha Pokemon, it created pokemonand its base stats is the highest over any other Pokemon, Its the best Pokemon on paper, but when you play with it its not the BEST Pokemon out there. If you level all Pokemon to level 100 then Arceus would be the best, at level 100 it learns the move jugment. Also, if you catch a high level Pokemon, like a level 70 lugia, then level it up to 100, it wont be as stroung as if you got a level 20 lugia and level it up to 100, this is because the Pokemon earn more stats when you train them and not as much in the wild. So its best to get slightly lower level Pokemon, not the highest. Now, the best Pokemon in Pokemon hh and ss. This is only the best one avaulable to catch, without cheats or trading. The best Pokemon is probobly Lugia.