Onslaught from axe notable not affected by buff duration nodes

It's not an issue with onslaught itself, as it works with deathrush ring.

i'm not a mod, but i believe it is because the nodes you're speaking of read "increased skill effect duration".

since onslaught is a passive, and not a skill that you use, it does not apply to these nodes.

The "increased effect of buffs on you" nodes should work, however.