Had a kinda silly idea for a Flashback build that probably wouldn't be able to keep up with trade league builds, but might work okay in SSF. Only problem is it relies pretty heavily on Cybil's Paw, and even though that's not a particularly rare item I don't want to have to rely on it just randomly dropping. Is there a decently reliable way to get one without trading for it? Do you want to poe buy items? If you do, you can visit U4GM to have more poe currency cheap about this.

If you plan on doing it ssf i would recommend starting off as something close to your target build, but not requiring uniques. My friend did spectre summoner withou ullr till 91 on ssf before they dropped. Instead of doing something like srs + wicker he went the slowest solar guard summoner i had seen. In ssf you don't have much else to use your regrets for, so i think not fully committing to your build before you have the necessary items might be the safest bet. Ideally a build that requires no uniques and with a generic tree so if you find that crazy item you can transition your build.

I've played full SSF MF on a totem char and found at least three Cybil's on a char that went to level 94. I think I had around 250 IIR / 50 IIQ. Without MF your best way to try and get it is by using Chance Orbs on all the Thresher Claws you find. Chancing items will usually yield something if you keep trying, I've chanced unique staves to get access to Vinktar Square in SSF and succeeded twice. The problem is that at first you'll have to save Chances because you need them to buy the Zana maps for faster progression, but later in maps you can start chancing items.

I generally do the same for other important SSF uniques like Cloak of Defiance, Covenant or Vis Mortis. There's a Beast recipe that lets you reroll a unique, which is capped by the itemlevel of the unique you're re-rolling. In other words, if you have a low level unique near the level of Cybil's then you'll have a better chance of getting it through the Beast recipe.

In the last, Whenever you want a unique that's somewhat easy to chance, I'd recommend you edit your loot filter to highlight the base item. In this case, Thresher Claw has only 1 unique, so I would also add a super loud sound to unid'd uniques with this base, so that you're sure not to miss it if it actually drops.