Balak

From Mass Effect Wiki

Ka'hairal Balak is the leader of a batarian terrorist group that raids Asteroid X57 in 2183. Unlike the other batarians, who only planned to make a quick slave grab,
Balak is on a mission to crash Asteroid X57 into the human colony of Terra Nova.

Balak hates humans because they claimed territory and resources that he believes should have belonged to the batarians during
the early stages of humanity's major expansion into the Skyllian Verge. He sees his actions as reprisal for the Skyllian Blitz on Elysium.

Balak rigged the fusion torches propelling the asteroid to execute burns that put it in a collision course with Terra Nova.
After Shepard lands in the Mako and begins on shutting down the fusion torches, Balak sends his forces after the Commander.
Balak then hunts for the hiding engineers in the main facility who were aiding Shepard. When he finds Kate Bowman, he demands to know who is attacking his people;
when Kate refuses to answer, Balak kills her brother and sends Charn to find Shepard.

When the Commander launches an assault on the main facility, Shepard confronts Balak, who has planted a bomb in the offices where
the hostages are being held. Balak talks angrily about the thwarted Skyllian Blitz (if Shepard is a War Hero, Balak holds Shepard personally
responsible for the Blitz's failure) and about Torfan (if Shepard is Ruthless, Balak accuses Shepard of murdering batarians).

Shepard has a choice to make: either attack Balak to ensure his death, or release him in order to save the hostages, including Kate Bowman.
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In my headcanon, Balak was contacted by a human slaver named  Aldon Stanford, who encouraged him and his batarian troops to raid Asteroid X57 and rig the fusion torches that was propelling the asteroid close to Terra Nova for prospecting, and cause it to collide and destroy the planet.

In truth however, Stanford tricked the Balak and troops into attacking the asteroid and propel it towards Terra Nova, knowing this would get Seidra's attention, and hoping it would get her killed trying to save Terra Nova and the Asteroid X57 from a terrorist attack.

But instead, Shepard and her team defeated Balak and his attack group, yet she had to let Balak himself go in order to defuse three bombs
that was planted in the main facility and save the hostages.

When Stanford learned the Seidra had successfully thwarted the attack near Terra Nova, He sent a former leader of the the Terminus pirate bands. 
Elanos Haliat, to lure Seidra into a deadly trap on Agebinium, which of course led to another failure when Haliat was killed.

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