http://www.smogon.com/dp/pokemon/pichu
[OVERVIEW]
Pichu is an extremely outclassed threat. Pichu, like its big brother Pikachu, has horrid stats at first glance, but it ultimately isn't completely useless. Its speed reaches a stat of 15, allows it to outspeed common Pokemon that sit at the 14 Speed stat. Pichu can perform different jobs, albeit sweeping or leading. Overall, Pichu is a Pokemon that an opponent should think twice about before moving.
[SET]
name: Choice'd
move 1: ThunderPunch / Toxic
move 2: Volt Tackle
move 3: Return
move 4: Iron Tail
item: Choice Band / Choice Scarf
nature: Jolly
evs: 118 HP/ 196 Atk/ 196 Spe
[SET COMMENTS]
- ThunderPunch for a reliable STAB attack, while Toxic can be used to drain the opponent's HP
 - Volt Tackle for strong STAB move
 - Return hits hard against Pokemon that are resistant to Electric type moves
 - Iron Tail is used instead of Grass Knot because this is a physical set
 - Choice Band is the recommended item because Pichu's low attacking power greatly appreciates any boost in that area
 - With Choice Scarf, its Speed reaches 22, allowing it to outspeed all non-scarfed Pokemon
 
[SET]
name: Life Orb
move 1: Volt Tackle
move 2: Thunderbolt
move 3: Return
move 4: Hidden Power Ice
item: Life Orb
nature: Hasty/ Adamant
evs: 36 HP/ 200 Atk/ 76 Sp. Atk/196 Spe
[SET COMMENTS]
- Life Orb boosts the power of Pichu’s below average attacking stats
 - Volt Tackle for a strong STAB move
 - Thunderbolt is used of ThunderPunch here due to its higher base power
 - Return provides good coverage
 - Hidden Power Ice hits both Ground and Grass types
 
[SET]
name: Encore Orb
move 1: Volt Tackle
move 2: Encore
move 3: Return
move 4: Substitute
item: Life Orb
nature: Hasty/ Adamant
evs: 112 HP/ 200 Atk/ 196 Spe
[SET COMMENTS]
- Pichu is the only electric type in LC to have access to Encore
 - Encore is used to force a switch, then Pichu can attack with Volt Tackle as they switch
 - Return provides more coverage
 - 112 HP evs allow Pichu to set up Substitute four times
 
[ADDITIONAL COMMENTS]
- Pichu appreciates any sort of status ailment on the opponent’s Pokemon, especially paralysis, sleep and freeze.
 - Also benefits from entry hazards such as Stealth Rock.
 
[OPTIONAL CHANGES]
- Choice Specs set with Thunderbolt, Grass Knot, Hidden Power Ice and Signal Beam is a viable option
 - Nasty Plot Pichu with Thunderbolt, Grass Knot and Hidden Power Ice is also plausible
 - A Leading Pichu could also be used with Fake Out, Encore, Thunderbolt, Protect
 - Thunder Wave may be used over Protect to cripple the opponent's Pokemon and make it easier for your teammates to deal with
 
[TEAM OPTIONS]
- Stealth Rock set-up users such as Bronzor
 - Because all three have a common weakness to Ground, a Scarf Gligar is beneficial to the team
 - Scarf Gligar can also scout the opponent's team with U-turn
 
[COUNTERS]
- Pokemon with priority moves, such as ExtremeSpeed Dratini and Fake Out + Vacuum Wave Croagunk, can easily beat Pichu.
 - Chinchou doesn't take much damage from super effective Grass Knot, is resistant to HP Ice and is immune to Electric attacks.
 - Pokemon that outspeed Pichu have a easy time defeating it.