Just like the title says, Brilliant Cleave is behaving strangely with Dark Transfusion and Harbinger. (And with more testing, also Harbinger's passive effect is bugged.)
While testing on the PTS (after wondering if Brilliant Cleave counted as a Life Drain for the purposes of Harbinger,) I encountered the following: Dark Transfusion (which nerfs all non-Life Drain healing but does not nerf Life Drain healing) does
not nerf Brilliant Cleave's healing ticks whatsoever, which would suggest that Brilliant Cleave is a Life Drain. However, Harbinger is not buffing Brilliant Cleave healing at
all. Its initial/passive boost to all healing and all damage isn't affecting Brilliant Cleave's damage or healing numbers whatsoever, (
or base Cleave's damage numbers, or Shadow Blast's which I took for comparison, only touching Lifedrain's damage
but not its healing which makes me wonder if Harbinger is the bugged thing here)
and attacks with Brilliant Cleave do not proc Harbinger stacks whatsoever
(but it DOES benefit from specifically the healing part (but not the damage part) of Harbinger stacks procced from another source!) Something funky's going on here so I figure this is worth reporting.
Tested with: a level 40 Hybrid with no slotted devices except for Darkspeed and Brilliant Cleave, no slotted gear whatsoever, Str/Dex/Int with "The Hero" Innate Talent, all three of each +8 Superstat and +5+5 Superstat Talents, and nothing taken whatsoever in the spec tree menu. The following powers were taken in testing in order:
Bludgeon R1 (EB)
Cleave R1 + Brilliant Cleave
Guard R1
Harbinger R1
Spirit Reverberation R1
Dark Transfusion R1
Lifedrain R1
Shadow Blast R1
Arcane Vitality R1
Something just seems... wrong here.
*Harbinger is supposed to provide a bonus to all damage and all healing passively while slotted as it says in its tooltip and powers menu description, but it is not passively boosting the damage of
any of the specified powers
except Lifedrain. Additionally, it is
not passively boosting the
healing of Lifedrain whatsoever, however it
is passively boosting the healing of Arcane Vitality.
*Harbinger is supposed to provide a stacking buff to
Life Drain healing and Life Drain damage when using Life Drain powers. (There's something about damage resistance in there too but I'm not testing this.) This is correctly boosting Lifedrain's damage and healing, but weirdly enough, boosting Brilliant Cleave's
healing but
not its damage. (Additionally, attacking with Brilliant Cleave does not refresh Harbinger stacks.) Harbinger stacks appear to otherwise be working as intended, and are not providing bonus damage or healing to non-Life Drain powers.
Wrapping that up; Brilliant Cleave is buffed by Harbinger "stronger Life Drain power" stacks for healing but not for damage, which suggests that it's a Life Drain effect but something's gone wrong in the code. Brilliant Cleave's healing is not nerfed by Dark Transfusion's "nerf all incoming heals except Life Drain effects" debuff, which also suggests that it's a Life Drain effect. However, Brilliant Cleave attacks do not proc or refresh Harbinger Life Drain buff stacks, and do not benefit from their damage boost, which seems buggy considering what I just described. Furthermore, Harbinger's passive bonus seems royally bugged: its description describes it as buffing all damage and healing but it appears to only buff Life Drain damage but
not healing (I eyeballed Devour Essence in the power picker with it too) and non-Life Drain healing (Arcane Vitality, and I also eyeballed an unpicked Iniquity from the power picker.) Life Drain healing isn't being buffed by Harbinger's passive effect even though it should be, and non-Life Drain damage isn't being buffed by Harbinger's passive effect even though it should be.
My assumption, however incorrect it may be, is that Brilliant Cleave's bugginess with Harbinger is a symptom of Harbinger's own bugginess, and Harbinger buff stacks touching Brilliant Cleave's healing but not its damage makes me feel like the PVD's healing and damage are two separate powers glued together, the former some sort of weird Life Drain Combo that only directly affects allies rather than enemies and the former a more traditional one-two-three Combo power with variable AoE. But yes, this is what I ran into in testing.
Lastly, reconfirming what I said at the start of the post, this was all tested on the PTS with the prior described character,
not on Live.
Oh, and one last thing, I swear. Relevant to me writing this post because of experimenting with Brilliant Cleave in the first place, but that PVD's VFX is still bugged.