What exactly is the special effect of Sequencer and Peytral? All it says in the description is "attack/defense increases under certain conditions". What are these conditions?

Well, now that I (SPOILER)defeated the Red and Blue Kings, maybe I can attempt General Training II again. I actually put whatever on my units and managed to beat Blue King on my first try. I actually managed to nab some nice loot with Adelle and Luso while my other guys attacked him from afar with Moogle Lance/Air Render. It was pretty awesome seeing them get owned with Magick Frenzy, I didn't think about that Rend MP thing. He casts Quake, then double attacks everyone who gets hit. xD Thankfully he just used up most of his turns using that "Reveal Weakness" skill that lowers your defense. I just had Adelle throw weapons at him because it did more damage than anything else I had to use. O_o