This is a question I have for ZOS, because my Live build is centered around using champion points, buffs and armour passives to achieve very large heal percentages with Dragon Blood, specifically the Coagulating Blood morph.

First, let me start off by showing you a picture taken on the PTS using the same build I would use on Live, but as an Argonian (since they have the Quick to Mend passive):


You might assume that this is edited to make a point, but I will include a video at the end of this thread of me just jumping off cliffs and selfhealing.

So as you can see in the picture I achieve 94.7% of missing health returned with my PTS Argonian Dragonknight template toon. This is outside of Cyrodiil mind you.

@ZOS, is it intended that we should be able to buff Dragon Blood like this or is it an unfortunate exploit of mechanics that was never supposed to happen?

How I achieve this healing percentage:
100 points in Blessed: Increases the effectiveness by any healing you initiate by 25%.
100 points in Quick Recovery: Increases the effectiveness of healing received by 16%
7% from Rapid Mending since im wearing 7 heavy armour pieces: Increases healing received by 1% per piece of Heavy Armour equipped.
8% increased healing from having Coagulating Blood active: Also grants Major Fortitude and Minor Vitality, increasing Health Regeneration by 20% and healing received by 8% for 23s.
12% from having a Draconic Power ability active (in this case Coagulating Blood): Increases healing received by 12% while a Draconic Power ability is active.
30% increased healing taken from Igneous Shield (activated before using the selfheal): The shield also grants Major Mending, which boosts the effects of your healing abilities by 30% for 7 seconds.
9% increased healing taken from Quick to Mend (Argonian passive): Increases healing received by 9%.
10% from the Ritual Mundus Stone: Increases healing effectiveness by 10%. Further increased by 7.5% from 1 piece of Legendary Divines traited piece of gear = 10.750%.
8% increased healing taken from set bonuses, in this case the 3 and 4 piece effect of the Leeching Plate set from the Imperial City dungeons. On the Live server I am using Eternal Yokeda which has the same healing stats.
NOTE that on the PTS character I only have 8% from this set, I have been told there are other sets with this set bonus of healing, like the Unassaible set, which comes with jewellery, enabling you to wear 5 pieces, which would boost healing taken to 16% because of its two 4% increased healing taken buffs at 3 and 4 pieces equipped. I have not tried it, but you could also use Healer's Habit which would boost healing done by 8% at 5 pieces equipped.

I hope a ZOS official can confirm or deny whether or not this is intended. I do not hide potential exploits like others would for selfish reasons, I think sharing things like this helps fix problems with balance and ensures nobody has an unfair advantage because of race or class. I am 100% convinced that the Quick to Mend passive is a very large problem in this, along with the Blessed passive in the Apprentice tree and the way the Healing Taken buffs are calculated separately instead of all at once. The whole math behind the percentages is way off where it should be, with percentages sometimes working additively, instead of multiplicatively as they should. This is also the reason why 100% damage mitigation builds were possible on the PTS until they fixed them.

Lastly, here is the video showing that I am not lying about the severity of these heals (look at the chat box in the bottom left):
https://www.youtube.com/watch?v=EdV4t-yXNdk

EDIT 1:

Changed some gear around on my Khajiit Dragonknight on Live, with 5% from Mundus stone (6.3% because of Divines trait). Here's a video of me achieving 91% healing with my Khajiit using 5p Twilight's Embrace (suggested by @bigereard on a different post), 4p Unassailable (also suggested by him) and 2p Yokeda:
https://www.youtube.com/watch?v=X2S3xYaqB38&feature=youtu.be

EDIT 2:

Actually maxed out Quick Recovery, and I am running 5 pieces of Divines purple gear boosting Ritual Mundus from 5% to 6.625% (5 x (6.5 x 5)).

Here is a picture of my Khajiit Dragonknight pulling off 96.1% of missing health returned using Dragon Blood (this is before the Ritual Mundus stone buff mind you):


EDIT 3:

Changed the title so it's not making people lose their minds over the fact that I called this a possible exploit ( '-.-)

EDIT 4:

How I achieved 96.1% on a Khajiit before Update 7:
100 points in Blessed: Increases the effectiveness by any healing you initiate by 25%.
100 points in Quick Recovery: Increases the effectiveness of healing received by 15.8%
7% from Rapid Mending since im wearing 7 heavy armour pieces: Increases healing received by 1% per piece of Heavy Armour equipped.
8% increased healing from having Coagulating Blood active: Also grants Major Fortitude and Minor Vitality, increasing Health Regeneration by 20% and healing received by 8% for 23s.
12% from having a Draconic Power ability active (in this case Coagulating Blood): Increases healing received by 12% while a Draconic Power ability is active.
30% increased healing taken from Igneous Shield (activated before using the selfheal): The shield also grants Major Mending, which boosts the effects of your healing abilities by 30% for 7 seconds.
5% from the Ritual Mundus Stone: Increases healing effectiveness by 5%. Further increased by 32.5% from 5 pieces of Epic Divines traited piece of gear = 6.625%.
Gear:
2 pieces of Yokeda, 4% increased healing.
4 pieces of Unassailable, 8% increased healing.
5 pieces of Twilight's Embrace, 10% additional healing: When you are healed, gain 10% additional healing.

*** Please note that this is BEFORE UPDATE 7, which adds 10% bonus from Ritual Mundus Stone and boosts Quick to Mend argonian passive from 6% to 9%. By my rough estimations, maximum amount of healing you can do with this set will be near 110% on an Argonian and about 100% on other races. I will update this post after Update 7 goes to Live. ***

EDIT 5 - After Update 7:


19468 / 19401 = 100.3%..

Adjusted the title slightly.