Virizion is a stationary Legendary Pokemon meaning that it will reappear after you have defeated the Elite4.
Anyhow many Pokemon can be used to catch Legendary Pokemon, however some Pokemon do it exceptionally well.
To catch Virizion I recommend using Amoonguss.
Amoonguss is bulky and resists all of Virizion's STAB moves like a pro
It has access to Spore and can ware Virizion down with Sludge Bomb which will not be doing a huge amount of damage due to it only having a relatively decent Special Attack. I recommend using an Amoonguss as such to catch Virizion:
Amoonguss (@ Leftovers)
Trait: Any really
prefered Nature: Calm
- Sludge Bomb
- Giga Drain
With this moveset, catching Virizion shouldn't be hard at all.
If you were to battle it at night I would recommend using Dusk Balls to catch it. Spamming Timer Balls is always fun and will let you catch it somehow. The trusty Ultra Balls can always be used as well :)