I just want to report a few tests on black flame I performed the other night.
Firstly, many of you know this, but for those who browse forums instead of the wiki home, black flame has been confirmed to do Fire damage. There are a few spots around the wiki that lists it as physical and some youtubers seem adamant about it dealing physical.
I decided to test black flames stamina reduction potential v.s. shield stability. The toon used is sl 50 with 64.8 stamina (14 end fap ring). I choose to test on him so I could see how black flame would affect mid level questers who may not be pvping.
8 Shields were tested. The criteria was how many casts does it take to break guard
No Grass was used during the tests
Format: shield name/stability/# of casts to break guard at 64.8 stamina
Silver Knight/76/2
Grass Crest/61/2
Black Iron/80/4
Crest/66/2
Spider/56/1
Wooden/62/1
Dark Hand/30/1
Havels/84/5-8
Havels shield as expected performed the best. The 5-8 is due to me letting go of the shield on some runs to see how much stam I could recover between spams. For all other shields I never let the shield down during the spams.
I decided to test poise and black flame as well..
The tests confirmed that one would need 62 poise at the minimum in order to tank one cast.
Iron Flesh on a 0 poise toon absorbed 4 casts. I suspect it could have taken more however my toon died from taking 5 while naked lol.
Also, the bellowing ring and dusk's crown do not increase the guard breaking affect,only its damage dealt.
The glove used was ascended +5.
I tested the usefulness of Flash Sweat as well...
with Fire Def 95 my 1022 hp toon was reduced to 532 hp after one black flame no buffs added. 490 dmg inflicted
with Fire Def 95 my 1022 hp toon was reduced to 707 hp with Flash Sweats protection
315 dmg inflicted
A difference of 175 dmg!

That about sums up my research. HUGE thanks to Chibininja for frying my toon helping me gather the info
This was done at the request of some forum members, let me know if you guys would like more in depth tests. I wanted to see if there was any interest before I went all out.