Where do I find EV reducing berries in Pokémon black?

Question

I got a Lucario and I was going to fight Cynthia because I saw a video of a guy soloing Cynthia with a Lucario. So I was doing that when I realised my Lucario was quite slow and I decided to train Lucario's speed stat. I went on route 1 at the water and I trained the speed stat till I reached the max I could because other stats were pretty high. I battled Cynthia (I saved before battling her). Before I EV trained my Lucario was faster than her Spiritomb but when I came back after the EV training my Lucario was somehow slower. I think I might try to lower the attack stat as my Lucario has high Sp.Attack and Speed. Where are the berries to lower EVs? Please tell me if you know where they are in black or if there are any ways for me to increase the speed in general. My stats on Lucario are: 141 attack, 88 defense, 167 Sp. Attack, 97 Sp. Defense, 141 speed(the number for the speed is blue for some reason.)

Answer 1

While they can be found in the sequels, EV-reducing berries cannot be found in Black and White without trading with B2/W2. Source

Answer 2

Actually, you can get EV reducing berries in Black/White by doing a spin trade (eggs) in the union room with a certain number of people. (I think 4). If the spin trade lands on a reward spot, you’ll get a bonus Berry.