Pichu's Fling can be B-reversed just like most other B moves. Within the first few frames after starting the move, if you press backwards on the control stick, Pichu will turn around and fly the other way. But this move has something odd about it. Normally if you try to B-reverse too late, nothing happens. If you try to B-reverse this move too late... ...Pichu doesn't move sideways at all. This also happens if you B-reverse it twice, so if you can't get the timing down, try spamming left-right-left-right as fast as you can. The move works like normal in all other ways. You can still cancel it into aerials or specials (except Fling). You still can't jump or airdodge out. It still counts against the maximum number of times you can use Fling in midair. And, perhaps most importantly, it still sends opponents in the direction Pichu is moving. At low percentages, it can be hard to combo out of regular Fling, since Pichu flies past its enemy. This makes upwards Fling a much better choice, because it guarantees that PIchu and its opponent won't get too far apart. At higher percentages, the move will send the opponent much higher than Pichu. Since Pichu can't jump out of Fling, it has only two options: chase with Agility/Volt Switch, or attempt to hit with Thunderbolt. Or, of course, you could go back to normal Fling. Since Thunderbolt starts from so high up, it can combo even at near-kill percentages, when the opponent flies way too high for Agility to reach. The problem is, Pichu can't move sideways before Fling ends, so Thunderbolt will miss if they DI left or right. In that case, your best bet is to use Agility to get back beneath them (you'll have to read their movement), and then Thunderbolt. Finally, you can use this to approach from below, but the hitbox ends before you reach the apex, so don't start it too early.