Piplup is great.Piplup may be weak with a घास type but it's super effective with drill peck and peck.Piplup is super effective with आग types too.As for electric types,you have to envolve piplup to learn dig.Also when आप envolve it, आप can learn घास 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 आप had a piplup, it can learn surf and waterfall when it envoles and then आप could meet the champion!Remember,first is a bug trainer so आप can beat with flying type moves like peck या drill peck.Next is ground which आप can use घास knot.Third is kind of आग 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 आप can use घास knot!