Successfully complete the indicated party member's Loyalty mission to
unlock the corresponding skill for Shepard, alternate colors for their
costumes, and increase the chance for surviving the suicide mission.
Note: Successfully complete the Advanced Training research upgrade for
your ship to be able to select the skills.

Armor Piercing Ammo: Archangel's Loyalty mission
Biotic Barrier: Jacob's Loyalty mission
Dominate: Kill Samara during her Loyalty mission, and have Morinth
replace her.
Fortification: Grunt's Loyalty mission.
Geth Shield Boost: Legion's Loyalty mission
Inferno Grenade: Zaeed's Loyalty mission
Neural Shock: Mordin Solus's Loyalty mission
Reave: Samara's Loyalty mission
Shield Drain: Tali's Loyalty mission
Slam: Miranda's Loyalty mission
Warp Ammo: Jack's Loyalty mission