After you have obtained the National Dex and fought your way to the Survival Area, you will discover that your rival is there, hanging out in front of the Top Trainer Café. Like in Diamond & Pearl, he will be willing to have a battle against you, but only on the weekend. His Pokémon start up at the same levels as the people in the café. However, they will get higher in stages until they reach a maximum of Level 85 for his starter. The method for this is not currently known, but the team data was extracted from the game. We'll keep you aprised on further developments

Rival Battle - Phase 1

Rival
If you picked Piplup
Staraptor
Lv. 61
Rapidash
Lv. 59
Floatzel
Lv. 59
Snorlax
Lv. 63
Heracross
Lv. 62
Torterra
Lv. 65
Rival
If you picked Turtwig
Staraptor
Lv. 61
Roserade
Lv. 59
Floatzel
Lv. 59
Snorlax
Lv. 63
Heracross
Lv. 62
Infernape
Lv. 65
Rival
If you picked Chimchar
Staraptor
Lv. 61
Roserade
Lv. 59
Rapidash
Lv. 59
Snorlax
Lv. 63
Heracross
Lv. 62
Empoleon
Lv. 65

Rival Battle - Phase 2

Rival
If you picked Piplup
Staraptor
Lv. 71
Rapidash
Lv. 69
Floatzel
Lv. 69
Snorlax
Lv. 73
Heracross
Lv. 72
Torterra
Lv. 75
Rival
If you picked Turtwig
Staraptor
Lv. 71
Roserade
Lv. 69
Floatzel
Lv. 69
Snorlax
Lv. 73
Heracross
Lv. 72
Infernape
Lv. 75
Rival
If you picked Chimchar
Staraptor
Lv. 71
Roserade
Lv. 69
Rapidash
Lv. 69
Snorlax
Lv. 73
Heracross
Lv. 72
Empoleon
Lv. 75

Rival Battle - Phase 3

Rival
If you picked Piplup
Staraptor
Lv. 81
Rapidash
Lv. 79
Floatzel
Lv. 79
Snorlax
Lv. 83
Heracross
Lv. 82
Torterra
Lv. 85
Rival
If you picked Turtwig
Staraptor
Lv. 81
Roserade
Lv. 79
Floatzel
Lv. 79
Snorlax
Lv. 83
Heracross
Lv. 82
Infernape
Lv. 85
Rival
If you picked Chimchar
Staraptor
Lv. 81
Roserade
Lv. 79
Rapidash
Lv. 79
Snorlax
Lv. 83
Heracross
Lv. 82
Empoleon
Lv. 85