The second part of the check.. Could be used against a enemy? I don't understand this power.

6 minutes ago, Luahk said:

The second part of the check.. Could be used against a enemy? I don't understand this power.

No. The F&D iteration of Battle Meditation is strictly designed to add bonuses to your allies. If you want to penalize your opponents, or turn them against one another, you use the Influence power's Emotion upgrade.

what using Dark Side pips does is turn your "allies" into pawns, essentially imposing your will on them, not just enhancing their combat effectiveness.

The narrative explanation is that by using the dark side to fuel this preternatural connection with friends and allies in battle, you are consciously or more likely subconsciously binding them to your will through your command and aid over their actions. As Battle Meditation is essentially acting like a Force Astromech to their Starship Body and reflexes, but an 'evil' Astromech might wish to take control of the Ship away from its proper pilot.

This in turn lowers their ability to resist further mental effects or focus as you suppress or force them to exert mental effort to keep themselves in control to the best of their ability.

So mechanically, it lowers their Willpower score which is linked to Discipline and Vigilance, which can be explained as them being too focused on your intrusions to worry about others.