Piplup is great.Piplup may be weak with a césped, hierba type but it's super effective with drill peck and peck.Piplup is super effective with fuego types too.As for electric types,you have to envolve piplup to learn dig.Also when tu envolve it, tu can learn césped, hierba knot to beat water types so easily!Don't forget it can also envole to Emploen and learn hydro cannon!And don't for get metal claw either!Piplup is also very strong with it's torrent ability.Piplup is cute and when it envoles to Emploen,it looks tough and it may be too!Also,if tu had a piplup, it can learn surf and waterfall when it envoles and then tu could meet the champion!Remember,first is a bug trainer so tu can beat with flying type moves like peck o drill peck.Next is ground which tu can use césped, hierba knot.Third is kind of fuego so Piplup can beat them easily with a water type move.Last, is a phychic type but I have no advice.Finally,the chamion's strongest pokemon is Milotic so tu can use césped, hierba knot!