So if I was in a triple battle, and I had a spiritomb, I would use a shedinja with mimic from the 3rd gen move tutor, and a Pokemon with entrainment, I would begin by having the entrainment Pokemon use entrainment. Then you have shedinja use mimic to get entrainment. Then you use entrainment with your shedinja and on spiritomb.
Left:
Spiritomb @ leftovers
EVS: 252 HP 252 Special Defense 4 Defense
Impish Nature (+ Defense -Special Attack)
- Protect
- Substitue
- Shadow Sneak
- Will-O-Wisp
Middle:
Shedinja @ Focus Sash
EVS: 252 Attack 252 Speed 4 Special Defense
Adamant Nature (+ Attack -Special Attack)
- Mimic
- Shadow Sneak
- X-Scissor
- Protect
Right:
Durant @ Focus Sash
Trait: Truant
EVS: 8 Hp 248 Attack 252 Speed
Joly Nature (+ Speed - Special Attack)
- Entrainment
- X-Scissor
- Endeavor (FEAR >:D)
- Iron Head
First, you would have durant use entrainment on a threat or just any Pokemon. Then, shedinja would proceed to use mimic on durant. Gaining entrainment. Spiritomb will use protect. Durant would be slacking off with truant, and shedinja would use entrainment on spiritomb. Spiritomb gains wonder guard!