Gearbox details the revamped siren class in its shoot and loot sequel.
The phaselock ability is the first earned in the Siren's skill tree, allowing her to bind an enemy from range in a kind of energy bubble
First, it takes an enemy out of a fight, providing a degree of crowd control.
Second, it locks the enemy in place, useful for turning fast-moving creatures into easy targets.
She's got support trees so she's also kind of a mystical healer and she uses her ability to grant health bonuses to herself as well as the team.
She can use her phaselock ability to revive another player, so you don't even have to be near somebody to get them up
She'll also be able to deal out plenty of direct damage by investing skill points in the Cataclysm tree.
She has a skill called Helios, and when a target gets phaselocked you get a huge aoe explosion and targets in that radius can get set on fire.