Justified, because Steadfast was always the inferior ability. Now if you had Inner Focus, that'd be tougher. --- Magical Scientist is more perfect than EotS because you get to shoot dinosaurs out of a turtle.
M!Lucario has adaptability, but my vote goes to Justified for the pre-Mega Lucario as it allows it to get an attack boost from switching in on a dark move, whilst steadfast will do... probably nothing.
Neither. Get Inner Focus. Would you rather get faster from flinching or not flinch in the first place? --- I'm not easily impressed; I'm usually oblivious to whatever's in front of me. Pokemon White 2 FC: 3139-7420-3142 - THIEF