In game, you will need a heavy hitting Pokémon that has the potential to do some serious damage to your opponents team. This article will be focusing on single battles in the current Sun&Moon meta. For this example, I will be using Pokémon #658, the Water/Dark frog ninja, Greninja.
Greninja is unique because of his hidden ability Protean, which changes its type depending on the move it just used. If you got the special demo of Sun and Moon for the 3DS, you will have a Greninja with a very unique ability known as Battle Bond, where after a successful knock-out happens, Greninja will essentially mega-evolve into Ash-Greninja, which gets a gigantic boost in its stats. But, for the sake of time and likeliness, we will be using a Greninja with Protean.
Greninja can be anything except for a wall, so for this we will be using a Special Attacking Greninja. The spread should look like this:
Held Item: Life Orb/Choice Scarf
Special Attack: 252
Special Defense: 0
Ice Beam/Hidden Power Fire
Greninja also has access to any Z-Move with these types, but do remember that Z-Moves can only be used once per battle.