Thank you Swampert. However, I can easily answer these questions using my own movesets. Make sure it has the ability Swift Swim for this moveset (besides, Storm Drain sucks) and make sure it is EV trained in attack like mine:
Rain Dance: Doubles Speed, increases power of Waterfall.
Waterfall: Good power, high accuracy, STAB, decent chance to cause flinching, powered up by Rain Dance.
Return: High power if your Pokemon is very Happy like mine is. High accuracy and can deal with Pokemon that Waterfall can't deal with.
Sweet Kiss: Confuses the foe. I've always liked this move ever since my Togepi in Crystal had it.