It doesn't seem to benefit from multi-hit, with blunderbuss or Sun and Moon I can only reduce 30s. Why is blunderbuss recommended for it? Am I missing something?

It has weird interaction with Refreshing Defense. With a few hits from a single-hit weapon, I increased it from ~100s to 600s. Doesn't seem to be exponential though.

It also can't remove the actual HoT of Unbending.

8 hours ago, yorname said:

.Why is blunderbuss recommended for it? Am I missing something?

Maybe because it also interrupts. Having multiple attack rolls can make sure to actually interrupt the target. And in case that target has (multiple layers) of concentration, multiple attack rolls might remove those, too. 

8 hours ago, yorname said:

It has weird interaction with Refreshing Defense. With a few hits from a single-hit weapon, I increased it from ~100s to 600s. Doesn't seem to be exponential though.

Huh - interesting find! 🤔

9 hours ago, yorname said:

It doesn't seem to benefit from multi-hit, with blunderbuss or Sun and Moon I can only reduce 30s. Why is blunderbuss recommended for it? Am I missing something?

Multiple rolls means several chances of success. Simple as that.

9 hours ago, yorname said:

It has weird interaction with Refreshing Defense. With a few hits from a single-hit weapon, I increased it from ~100s to 600s. Doesn't seem to be exponential though.

It also can't remove the actual HoT of Unbending.

Several duration affecting effect can interact in a super weird manner. Hard code bug.

13 hours ago, yorname said:

It also can't remove the actual HoT of Unbending.

huh, really?

i had no problem doing this with street sweeper. is it just some order of operations thing with blunderbuss shots and when concussive cleansing effect gets triggered?

13 hours ago, yorname said:

It also can't remove the actual HoT of Unbending.

Yeah, this is normal with BPM. Actual HoT of Unbending has fixed duration, can't be extended or reduced.