If it has 5 Perfect IVs and 10 Defense IVs, you can definitely use it in WiFi, but you can obviously try to breed for a better Riolu.
Since it has 31 SpA and 31 Att IVs, you can make it a mixed attacker, here's a set (for your specific Riolu):
Lucario @ Life Orb
Ability: Steadfast
EVs: 148 Atk / 108 SpA / 252 Spe
Hasty Nature
- Bullet Punch
- Vacuum Wave
- Psychic
- Close Combat