Drifblim
Stockpile
Focus Energy/Substitute
Charge Beam/Shadow Ball/Ominous Wind
Baton Pass
Item: Sitrus Berry/Lansat Berry/other pinch berry
Ability: Unburden
Nature: Modest/Timid
EVs: This will depend on what environment you plan to use Drifblim. Give it enough Speed to outspeed whatever you're afraid of after Unburden and split the rest between Defense and SpDefense.
Using Drifblim as a Baton Passer is nothing new, but I've had good luck with the oft-forgotten passable boosts of Stockpile and Focus Energy. With its massive HP and some EVs in Defenses, Drifblim can take several non-super-effective hits while it builds up its Defenses with Stockpile. After a Stockpile or two, it can even take a couple super-effective hits. Baton Pass doesn't pass the Stockpiles themselves, but it does pass the Defense and SpDefense boosts gained from them. The defensive boosts help to ensure that Drifblim will reach the appropriate theshold of health to activate its berry. Substitute can also help in this regard and works great with Stockpile. Substitute can also save Drifblim from critical hits that would otherwise shoot straight through its raised defenses.
Once the berry is eaten, Unburden activates and doubles Drifblim's Speed. It should then be able to Baton Pass its defensive boosts, possibly with a sub and another boost (Focus Energy/Lansat Berry/other pinch berry). The Speed boost from Unburden is not passed.
The other part of this set I'd like to talk about is Focus Energy. The researchers here at Smogon have found that the critical hit system has been altered since the 3rd generation (Ruby/Sapphire). Focus Energy now raises the crit-tier of moves by two levels instead of one, making it a much more viable move than in previous generations. Crits, in addition to dealing double damage, ignore any boosts to the target's defense scores and any drops to the user's attack scores.
It could be easily argued that Swords Dance and Nasty Plot are strictly better than Focus Energy, since they double the damage for all attacks, not just crits. However, Focus Energy has some clear advantages.
1. The boost applies to both physical and special attacks, making it useful for mixed attackers.
2. The boost cannot be lessened by Intimidate. In fact, critical hits negate Intimidate entirely as long as the user of the critting attack doesn't have a boosted Attack stat.
3. As mentioned above, crits ignore defensive boosts, making them ideal for taking down users of Cosmic Power, Bulk Up, Calm Mind, Reflect, and Light Screen.
Almost any Pokemon can benefit from the boosts that this Drifblim passes. However, it does have some weaknesses. First, the opponent's crits run right through Stockpile's defensive boosts. Second, the boosts are vulnerable to Roar and Whirlwind, just as any Baton Passer without Ingrain is. Also, this set makes Drifblim dead weight after one pass. When it comes back in, it will have lost its Speed boost from Unburden and will most likely have very low health.
As an example of a particularly good receiver of these boosts, I'll also present this Crawdaunt:
Crawdaunt
Crabhammer
Night Slash
Ice Beam/Avalanche/Brick Break/Superpower/Aerial Ace/Knock Off
Taunt
Item: Scope Lens/Razor Claw
Ability: Shell Armor
Nature: Brave
EVs: 252 HP, 120 Attack, 120 SpDefense, 18 Speed
Obviously this would be used in the UU environment. Shell Armor prevents critical hits that would otherwise break through Stockpile boosts. With Focus Energy or Lansat Berry passed and a Scope Lens or Razor Claw, Crabhammer and Night Slash are critical hits 50% of the time. The move in the third slot will be a critical hit 1/3 of the time. Taunt is here to prevent Crawdaunt from being the target of a Roar or Whirlwind.
