very helpful, thanks!As a Pichu secondary, your strategy should be:
-Don't get caught in laggy moves
-Avoid offstage battle as much as possible. Pichu can gimp, but will have to get you to 250+ to get an honest kill.
Armor also stuffs a lot of 'Chu's approaches. Balance armor moves with quick moves, since if you get caught in lag that's a free opening for Pichu. And lastly, this goes for any quick character match up; don't forget to move. I always catch myself standing still and waiting for the enemy to approach, but if you move you become harder to hit and make more openings for yourself.