What else is there to do after you beat alder?

There are a few things you can do:

1. Complete you Unova and National Pokedex.
2. Catch the Legendary Pokemon.
3. Train all of your Pokemon to Level 100.

Hope this helps!

Take my advice:

1.use types that have good attack like fire,secret moves, or reshiram's fusion flare will do great damage.

2.catch legandary Pokemon and train them to high levels like 80 through

Hoped that Helped!

You can make a dream team
You get all the Pokemon that you think are awesome and train them so they are almost invincible

In the city you meet cynthia in on the far right of it theres a mantion. Every day you can go there and fight a riches family member 1st day you fight 1 2nd day you fight 2 and so on (icant remember how many there are total) also you can rechallenge cynthia and or the elite 4 (each time they get stronger btw) well hope this helps!

You an catch all the Pokemon in the game or you can train and fight the elite four

You can also try to beat the elite four one hundred times I did so can you

Go to the bottom of the abbysal ruins in undella town. Altogether, the tresure is worth 2.5 million poke

In the abbyssal ruins what ever you do do not sell the plates they boost the power of moves and also change a certain Pokemon ps. NOT TELLING WHAT Pokemon!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Just do stuff that happens daily. Like in black city there is a guy in the biggest building that says if you beat a number of trainers he'll respond to your greed. Sure there are only 3 trainers outside but every day they will battle you again. Or you could make a list of the Unova Pokemon that you haven't seen. After that find the Pokemon you need, and evolve pokemon. Hope now your busy!!!!

Transfer all the good Pokemon to another game and then start over

I like to train 2 or 3 non legendaries up to level 80-85 ish. And then transfer to other games that have extended play after beating elite 4. Like sun or moon.