To the original argument about Sheik
Plaink said that a Falcon can never beat a top level Sheik
what about when Chu Beat you him with Pichu?
Can Pichus beat top level sheiks?
Of course a Pichu player can beat a top-level Sheik player.
It just takes these simple tactics:
1) knock the controller out of your opponent's hand repeatedly
2) biting and scratching is usually not against any tournament rules, use it wisely
3) blinding an opponent can help cut through their defense, try throwing something in their face like hot pepper. If you do not have such substance, see #2 (go for the eyes).
4) sneak on a handicap of lvl 9, this brings Pichu about mid-tier.
5) Unplug their controller (or cut the wire), this works well when combined with other techniques (particularly #3)
If you fail at the above techniques, chances are the Sheik player will chaingrab you to 999% and F-air you to your death before you can land a single hit. JV-5 stocked.
The only compensation is if you do actually land a hit on your opponent you can laugh at how terrible they are that Pichu actually landed a hit on them. Rub it in their face. If they say anything, just "no johns" them and laugh some more. Get your friends to laugh at them. Make them feel terrible that they had to resort to playing so cheap against a Pichu. Break their competitive spirit, and next time maybe they won't chaingrab you and you'll have an easier time getting a hit on them.