Yeah @Glen-i you can have one. I've got like 30 of them at this point.
I finally done it...
I can see why people fall down the rabbit hole of breeding Pokemon. It's time consuming but immensely satisfying.
Those berries are how you reset EV's. I think one of each will do the job.
The quickest way to train those EV's back up would be to shove vitamins down your Pikachu like the drug dealer you've always wanted to be. 1 Calcium gets you 10 Sp. Atk EV's. The maximum each stat can have is 252.
Each Pokémon can have a grand total of 510 EV's shared between all stats. So most people choose 2 stats, max them out and then put the rest wherever they feel it's appropriate.
So for Pikachu, I'd recommend maxing out Sp. Atk and Speed and then put the last bunch of points in HP, seeing as you plan on Dynamaxing it.
Another way of EV training is battling certain Pokémon over and over. For example, say if you beat a Rattata (I know it's not in this game, just roll with it), you'd get 1 Speed EV. Of course, beating 252 Rattata is insane... And kind of cruel.
Luckily, there are certain items known as the "Power Set" I can't recall where you get them. I think it's the BP shop in Hammerlocke. If you equip one of these on your Pikachu, then it gets an extra 8 EV's for every Pokémon it beats. So put on a Power Anklet, beat that Rattata and you get 9 Speed EV's instead of 1.
If you can't be bothered with that and don't have the dosh for drugs, then you can use Poké Jobs. You should have some jobs that raise base stats, one for HP and so on. Give your Pikachu a Power Anklet, send it on the job that raises speed for the whole day and when it gets back, that stat will be maxed out. Rinse and repeat for Sp. Atk (Make sure you change the Power item to the lens), and finally, give it a HP Up to finish the job.
There, you've EV trained your Pikachu in 2 days with almost zero input.
As for IV training, Hyper Training is how you do that, but your Pikachu already has perfect IV's so it doesn't need to do that.
Hope that's easy to understand. If you don't get something, let me know.
I'll gladly take one of those if you're giving them away.
I should be available from 6pm to 7:30.
Do you need anything in return? I've got Shield in case you need some version exclusives.
In order to get the Gigantimax version of any Pokémon, you need to catch that Pokémon in a Max Raid Battle where you fight against the actual Gigantamax form. Nothing else will do.