Banish

Banish
Banish (Racial) 1.5 sec cast 30 yds. range 100 Mana Banishes the enemy target, preventing all action but making it invulnerable for up to X sec. Only one target can be banished at a time. Only works on Demons and Elementals.
Usable by
Class	Warlock
Race	All
Properties
Type	Defensive
School	Shadow
Cooldown	None/Global Cooldown
Other information
Ranks	2
Related debuff
Magic Banish Invulnerable, but unable to act. Duration: X seconds

When you draw power from demons, it's a good idea to have a backup plan in case they disagree.

Banish is a Shadow-based Crowd Control spell, which makes an elemental or demon invulnerable for a given period.

Rank	Mana Cost	Duration	Level	Cost
1	100	20 sec	28	70
2	200	30 sec	48	2 50

Notes

Even though this spell is classified as a Magic effect, it cannot be dispelled, as it makes the target completely invulnerable.
Damage over time effects applied to the target will continue to count down when a target is Banished, but cause no damage.

If you are having problems with Banish breaking early then cast Curse of the Elements first. This will cause Banish to have a much greater chance of lasting its full duration.
Note that the only difference between ranks is the duration. Using a lower rank is perfectly possible, and handy, if you end up waiting a lot for a 30-second Banish to wear off. It only uses half the mana.
Banished mobs can be affected by a Voidwalker's Torment and Suffering abilities (and possibly the similar hunter pet ability as well?).
Mobs can be Taunted during a Banish. Communicate to your tank when the effect is seconds away from wearing off, they will appreciate the notice as it will allow them to place a Taunt effect on the mob and keep it from running out of melee range.
As with other Crowd Control abilities, it can be useful to employ the "Focus" system, especially using a macro such as this one.

May be used against another warlock's minion.
May be used on elementals such as a Mage's Water Elemental, a Shaman's Fire and Earth Elementals, and a Druid in Tree of Life form.
May be used against warlocks using Metamorphosis

Patch 2.3.0 (2007-11-13): Banish can no longer be cast on targets tapped by other players or groups.