Definitely Life Orb. You want to do the most damage with it, and Life Orb helps it achieve that by boosting the damage it deals by 1.3 and not locking it in to 1 move. Some people don't know what Choice Band does, it boosts physical attack damage by 1.5, but locks you in. Since Swords Dance sets are better for physical sets than Choice Band on Lucario, I'm using Life Orb for those reasons. Also, those EVs need improvement. Running 252 HP, 28, Spd, and 29 atk means you waste a lot of EVs. Also, since this is a sweeper, you should use the cookie cutter offensive Pokemon spread, the good old 252 Atk, 252 Spd, and 4 HP(or 4 in a defense stat, it doesn't really matter). Imo Justified>Steadfast. Flinches are very uncommon, and Knock Off is common, so you can get more Atk boosts, and boost your damage output. Tbh its abilities are not good, but Imo Justified>Steadfast for those reasons. Other then that, the set is good! I hope I've helped!
The final set:
Lucario @ Life Orb
EVs: 252 Atk / 4 SpD, 4 Def, or HP / 252 Spe
- Swords Dance
- Extreme Speed
- Meteor Mash
- Close Combat
Also, since it has an amazing physical movepool, you could replace Extreme Speed with another coverage move, but you don't have to.