>>13181919Lucario is extremely frail. He can't boost in someone's face unless they're setting up hazards or statusing (both of which you don't want and will rarely happen). Lucario also has a hard time getting in and reliably scaring something out for the Swords Dance on a switch. So, the idea is to pair SD Lucario up with something that will predictably lure a choiced pursuit on the switch.
This was all the rage with Latias in gen 4, as most Scizors ans Tyranitars would come in to either trap or revenge kill Latias with a choice band boosted pursuit. Sure, they'd kill your mon, but then they'd just hand you the game by letting Luke get in for free and get a free SD as they're to forced switch out due to pursuit doing pitiful damage on Luke's 4x dark resist.
This works with either ability. Though Justified is fun to work with on predicted crunches. It's more about team synergy than anything else.