Move 1: Belly Drum [Normal type]
Move 2: Psych Up [Normal type]
Belly Drum is a move that halves the user's HP but maximizes its Attack and Psych Up copies the targeted Pokemon's stats. Use Psych Up on its ally (Which used Belly Drum) and both Pokemon can benefit from the stat-raising effects of Belly Drum.

Move 1: Rain Dance [Water type]
Move 2: Thunder [Electric type]
Thunder is a move that has a massive attack power of 120, but an accuraccy of 70. Have the ally use Rain Dance to make the weather rainy, making Thunder always strike its target. This is especally effective aganst a foe that used Double Team over and over again.

Move 1: Leer [Normal-type]
Move 2: Earthquake [Ground-type]
1st Pokemon's type: Flying
2nd Pokemon's item: Metronome
Leer is a move that lower's both foe's Defense by 1 and Earthquake hits all Pokemon in battle exept the user. If one Pokemon (Which is a Flying type) uses a move like Leer or Tail Whip [Normal type] every turn, then the ally's move Earthquake will get stronger and stronger. And since the ally's item Metronome boosts a move's power if you use it repeatedly, you're sure to deal lots of damage.

Move 1: Focus Punch [Fighting type]
Move 2: Dark Void [Dark type]
Focus Punch has a massive attack power of 150 but always fails if the foe hits the user. Use Darkrai's Dark Void attack, which puts both foes to sleep, then use Focus Punch freely without worry. And to boot, if the sleeping foe somehow endures the move Focus Punch, Darkrai's ability Bad Dreams (Which damages a sleeping foe every turn) will finish them off.