Tranquility

From WoWWiki

Tranquility
Tranquility Channeled 30 PBAoE yd range 1650 Mana Heals all nearby group members for X every 2 seconds for 8 sec. Druid must channel to maintain the spell.
Usable by
Class	Druid
Properties
Type	Defensive
School	Nature
Cooldown	10 min
Talents
Improvement talents	Nature's Focus, Subtlety, Tranquil Spirit, Improved Tranquility, Gift of Nature, Empowered Rejuvenation
Other information
Ranks	5
Related buff
Tranquility Heals nearby party members for X every 2 seconds. Duration: 8 seconds

Now everybody breathe with me... in... out... in...

Tranquility is a high-impact druid group heal over time.

Rank table

Rank	Mana Cost	Heal Amount	Level	Cost
1	78%	351	30	54
2	78%	515	40	1 26
3	78%	765	50	2 7
4	78%	1097	60	3 6
5	70%	1518	70	9
6	70%	2598	75

Talent improvement

Nature's Focus gives you a 14-70% chance to avoid interruption caused by damage while casting the Tranquility spell.

Subtlety reduces the threat generated by your spells by 4-20% and reduces the chance your spells will be dispelled by 6-30%.

Tranquil Spirit reduces the mana cost of your Tranquility spell by 2-10%.

Improved Tranquility reduces threat caused by Tranquility by 50-100%, and reduces the cooldown by 30-60%.

Gift of Nature increases the effect of all healing spells by 2-10%.

Empowered Rejuvenation increases the percentage of your spell power that affects Tranquility by 4-20%

In the World of Warcraft: Trading Card Game.

Tips and tactics

This spell is possibly the greatest generator of threat in the entire game, so it's almost a guaranteed death sentence for the druid casting it. It's useful primarily for reducing group downtime after a big battle, or in advance of a runner or patrol add.
By spending two talent points into Improved Tranquility, you can completely remove the threat generated by this spell. This changes the spell from a group-saving death sentence to a simple group-saving second chance. This is especially recommended if you are the main healer. If adds have come into the fight and the tank needs an extra 8 seconds to regain control of the situation, this talent may save your group.
If used during combat, it's advisable to cast Barkskin beforehand, so the spell does not lose duration to damage. Additionally, warning the rest of your party beforehand can save the druid's life, because the tanks can prepare to force the aggro back onto themselves with taunts after the spell has started.
Not even Barkskin can save you from a well-timed kick or counterspell. These types of interrupts not only waste Tranquility for the length of its cooldown, but also disable the spell school, leaving a Resto helpless. Given that your druid will be waving their hands in the air, causing the air to glitter, and producing a distinct noise, it is unlikely to pass unnoticed in PvP.
The massive threat generation can be useful for a tanking druid, but it can be hard to time. It is also likely that the shift out of form will spike damage beyond what Tranquility can recover.
The "group" affected by this spell is the player's party, within a 30 yard range of the druid.