Implementing these changes should fix Vengeance Demon Hunter tanks in everything from raids to M+ (current 8.2/8.1.5 changes are in mind aswell).
Spirit Bomb (Current):
Consume up to 5 Soul Fragments within 25 yds and then explode, afflicting nearby enemies with Frailty for 20 sec and damaging them for (22.113% of Attack power) Fire per fragment.
You heal for 10% of all damage you deal to enemies with Frailty.
Spirit Bomb (New):
Consume up to 5 Soul Fragments within 25 yds and then explode, afflicting nearby enemies with Frailty for 20 sec and damaging them for (75% of Attack power) Fire per fragment.
You heal for 20% of all damage you deal to enemies with Frailty.
Gluttony (Old):
Consuming a Soul Fragment has a chance to activate Metamorphosis for 5 sec.
Gluttony (New):
Consuming a Soul Fragment has a chance to activate Metamorphosis for 7 sec.
Fel Devastation (Old):
Unleash the fel within you, damaging enemies directly in front of you for [(15.561% of Attack power) * (10)] Fire damage over 2 sec. Causing damage also heals you for up to [(40.95% of Attack power) * (10)] health.
1 Minute Cooldown
Fel Devastation (New):
Unleash the fel within you, damaging enemies directly in front of you for [(15.561% of Attack power) * (10)] Fire damage over 2 sec. Causing damage also heals you for up to 45% of Maximum Health.
Cooldown reduced to 40 Seconds
[Shattered Souls] (New):
Added: Consuming a Soul Fragment also reduces magical damage done to you by 1%, for 6 seconds, up to 15 times - Consuming additional Soul Fragments (beyond 15) does not extend the duration of the buff.