The reason for it having Truant is because, although it can not be removed by Entrainment you can give the opponent Truant with it. Here is a good set for it.
EVs: 252 Speed, 252 Attack, 6 Hp
Entrainment DOES work with Truant and is the devastating part of this set. Iron-head is for STAB, and Flinch. X-scissor is STAB. Stone-edge is coverage and T-wave is for if you really want to be annoying.
But beware this is so annoying that people may get angry if you use this on them.