>>22121407Steadfast is only useful when you use Fake Out on your Gallade in doubles assuming he doesn't take too much damage. You can also hope your opponent lands a flinch on you, but both are hazardous to use.
Justified is slightly easier to use since switching in on Knock Off gets you a free boost, again assuming Gallade can take the hit.
There's also a nice gimmick in triples involving Beat Up and Justified that is basically a Belly Drum that cuts slightly less HP at the price of using 2 mons in the same turn.
Both abilities require using high risk high reward strategies to reach their fullest potential and I can't guarantee these will work 100% of the time , so whichever strategy you want to use is entirely up to you.