Sorry for the bump, but I noticed that some of this information is wrong-ish:
And because Pichu has a good recovery, he also has a decent edgeguard vs Doc. If you haven’t understood this yet, understand that Doc’s recovery is terrible, so he doesn’t get ANYTHING free. Even though it’s Pichu, in the event that you wind up off the stage, you can’t be predictable.
Pills aren’t failproof, he can nair through them. You can’t take the low road all times, you’re liable to get thunder jolted, and heaven forbid if you don’t want to sweetspot. That’s asking for F.smash and thunder.
Pichu's whole game is pretty much just trying to gimp you. His edgeguarding isn't bad. What I've noticed is that a lot of pichu's standard edgeguard stuff (tilts and things) won't work sometimes because of Doc's silly upB hitbox, but when he is at low percent he can CC dtilt -> crap. so you should watch out for that (the one time that you actually play against a pichu).
You don't really want to be under the stage at all. Doc is kinda slow in the air and If the pichu is smart he will send some jolts around the side of the stage (those will kill you if they hit you) or he will send a thunder down right in front of the ledge (this prevents you from sweetspotting it), then he'll nair you or something.
He can also ledgedrop -> nair/dair/fair and it will kill you (he will be able to make it back always).
If you try to recover high, you can be doraki-thundered (Pichu can do this on like every stage, but me and ICG are the only two Pichus who do this though). This usually will just get you a little percent, but it sometimes will set up stuff for him.
Pichu’s Quick Attack: Same applies for Pikachu. When Pichu does quick attack, at the point where he can input a 2nd command, he scrunches up (to do the 2nd attack). During this time, his hitbox stretches to double the length. Because of this, Pichu cannot sweetspot the ledge from below, because he’s scrunch and poke his head over it. Caping this is free.
this is true, but you won't get a free cape if the Pichu is smart at all (Unless its Battlefield). Pichu can do the first part of his agility (so that it falls short of the ledge), then slightly angle the second and it will flip him up into the ledge (I believe that this won't work for pika though). But you can pull some stupid stuff on Battlefield and Pichu will have a little more trouble gimping you there, however he is mobile as hell on BF, so the matchup kinda depends on how the Pichu plays.
sorry for bumping this, I know that nobody really cares about the Pichu matchup, but Idk, maybe this will help you that one time you actually do run into a Pichu player :\
not trying to contradict the OP, its a very good guide, just puting in my own input.
also... why would he thunder OoS <_<
there is like... never a situation in which I see that being useful.
Jolt OoS maybe. In all likely hood, if you attack his shield, he's gonna Usmash you (Pichu, unlike pika, has a strong usmash behind him, so you aren't safe there)