With Pokemon Sun and Moon coming out in just another week, someone on the internet named richi3f has created a website that you can use to plan your Pokemon Sun and Moon party, picking all six Pokemon that you would likely want to be challenging the endgame with, whether through the Elite Four or whatever endgame challenges there are.
The planner, which you can find here, allows you to go through every available Pokemon in the game to think up the optimum party that you want to take through the last part of the game, including every Alola Pokemon (which were leaked with the demo), and all of the Pokemon from previous generations that will be available on the Alolan islands in celebration of the Pokemon franchise’s 20th Anniversary.
In addition to having all of the game’s Pokemon in it, the Pokemon Sun and Moon party planner also includes a function that lets you know the type advantages and disadvantages of your team, so if you think that you might have too much of a weakness to something (such as me, where my team of Decidueye, Tapu Koko, Mudsdale, Lycanroc, Silvally, and Kommo-o has three Pokemon weak to ice) you can adjust it to a Pokemon that you might like.
If you don’t want spoilers, of course, then you probably shouldn’t follow the leak, unless you’ve decided a week is too long for you to resist and you can actually look at the team thing in order to look at all of the Alola Region Pokemon you can see.
The Pokemon Sun and Moon party planner is available at the link above, so if you’re already wanting to plan ahead and see what Pokemon you want to have at the end of the game, go and take a look at it!