Build Improvement help

Any ideas on how I improve my Oni-Death Oath Cyclone Slayer?

https://www.pathofexile.com/account/view-profile/Marleyman65/characters

what do you specifically want to do? there are tons of ways to improve your build

and this oni-death aura build is kinda old-school...very hard to scale if you want to kill endgame fast, you have many mechanics that don't complement each other (oni is fire, death oath is chaos, haemo is bleeding, your char is like a generic crit build)
but if you are only doing this to clear maps it is not that bad i think...if you just want to pump a little more damage i recommend getting damage on rings, get a better rare amulet and upgrade your jewels, maybe getting a bit more attack speed is better too, the "overwhelm" ascendancy gives you more damage, up to you what you would respec
also get more utility flasks you are already leeching over the limit

from your skill tree:
1-Phase acro? you are better off pumping your armour and regen
2-Versatile stance, Spirit void are not that good for you, get thick skin, battle rouse, golem blood instead
3-i recommend getting Call to Arms and put enduring call somewhere, it will give you a ton of survivability

I would be happy to farm T16 maps really.

I do want to keep using Oni-Death Oath for no reason other than I like them. This is also my first attemt at building something for myself though I have hit a dead end above T12 maps.

honestly, farming t16 with your build is not comfortable
your items don't synergize well with your character
if you like the this popping combo because of the items, i recommend you do a research with chieftain or occultist builds
with occultist you won't use cyclone but it is easier to scale the chest's aura
with chieftain you synergize with oni much better, but the chaos damage will straggle behind

with slayer, in terms of EDPS, you have like 500k with cyclone, another 200k with death aura and your glove helps killing stragglers but this level of damage is low for T16, in my opinion the death oath and haemophilia are holding your char back, you need to be more focused to go over the tier threshold

perhaps it is even better to go with resolute technique, respec all your crit and acc nodes and put everything in sword damage % and some fire damage
you can also go for clusters but the cost will skyrocket

this trial and errors are part of the building process, i can't see any other options easily

well that is ok, there will be a free respec coming soon. I can swap the idea to another character and try again.

Thanks for the advice.