I heard ppl suggests 20 failstack for pri witch earring but its really hard for now and i wanna go for duo. Is it unrealistic expectation to have duo with 20 stack? Should i try or save them for future?

I made two pris for mark of shadow and witch's at 5 and 10 failtstacks respectively. I feel like I might have been lucky though. It's just RNG. 

The game is entirely RNG. I took a main hand from 1 to +15 with only 35 stones never going more then a 5 fail stack. On the other side ive taken 70 stones to do the same with armor.  Ive also seen ppl just force accessories to PRI with no fail stacks.

Ultimately its all your call

Thanks for advice guys. I spend 15 fs for pri but after that i ll try it at 10 fs.

The black spirit hates me is all I'm gonna say...