Banshee

Banshees are synthetic creatures derived from asari and mutated by Reaper technology. Banshees were first introduced in Mass Effect 3. Frighteningly intelligent, the Banshee are advanced pressure units usually found leading a Reaper strike force.

Banshees are created specifically from asari with active or latent predispositions to becoming Ardat-Yakshi.

Capabilities
Offensive

Banshees can charge their enemies (similar to Biotic Charge). They also have the ability to grab people and subsequently impale them with their hands, resulting in instant death. Sometimes they will stand still and briefly appear to charge up, after which they will scream and release a damaging biotic nova over a surprisingly large area. Finally, they throw powerful projectiles that move slowly but track their target. If one gets hit by the projectile, the shields are instantaneously destroyed and up to two health blocks are drained over time.

Defensive

Banshees possess substantial biotic powers, and can use their biotics to create barriers to protect allies. They can also use their charge ability to move quickly and unpredictably, which can make them very difficult to hit at range.

Tactics

 * When damaged after their barriers are knocked down, Banshees will sometimes drop to their knees and scream to regenerate. This scream does no damage, and is an opportunity to get in close for melee or shotgun attacks. This is risky however, as the banshee can grab you and kill you instantly.
 * In Multiplayer, Banshee instant-Kill grabs can be interrupted by a well placed sticky grenade.
 * Classes that chiefly uses powers (Engineers/Adepts) in Multiplayer may consider keeping the Cobra Missile Launcher equipped when engaging Banshees to reliably save squadmates if they get grabbed.
 * It's important to note that Overload does more damage to barriers than Warp, as counter-intuitive as it may seem. Of particular note is the Rank 6 evolution of Overload that doubles its damage to shields and barriers. Therefore, all squadmates who can use Overload should concentrate it on the banshee to remove her barrier. After the barrier is depleted, Warp is better for wearing down the armor.
 * In Single player, it takes a tremendous amount of damage from squadmates' attack to dislodge a Banshee's melee grab. Given the small window of time it takes for the Banshee to execute the melee-kill, it is wise to avoid it altogether.
 * In single player on Insanity, the scream will remove all your shielding (health unsure). For Vanguards, this can be avoided with a well-timed Biotic Charge (roll away immediately after) or Nova just as the Banshee kneels down.
 * It can be an efficient measure to use your squadmates' powers combined with yours to kill a Banshee. For instance choosing such powers as Reave, Dark Channel and Warp to take down her barrier and then shred her with an assault rifle. Might be risky, though acting fast and using squadmates' powers can finish her rather fast.
 * Be wary about sticking to cover. They can rapidly close distance and grab you, which is normally an instant kill.
 * Their only long-range attack is very avoidable and not an instant kill, even on Insanity difficulty. But it can (and probably will) deplete all of your shielding, and can in some cases, can take a bar or two or health away from you.
 * A Vanguard can successfully use Charge on a Banshee, but it requires great caution. The Vanguard should immediately dive away from the Banshee to avoid its instant-kill melee attack.  This can be a useful tactic, however, if a squadmate uses Warp on the Banshee beforehand, as the Charge will detonate Warp for substantial additional damage.  The detonation will also stagger the Banshee, giving an extra fraction of a second to escape melee range.
 * After unleashing the biotic nova attack, the Banshee will no longer be glowing. At this state, it is unable to either perform either another nova or teleport, making it the most opportune time to attack.

Morinth
If in Mass Effect 2 the player spared Morinth and killed Samara, then Morinth will appear in the mission Priority: Earth as a Banshee. She will not behave any differently from any other Banshee and must be killed as normal.