Grasyla definitely. It seems to be a form (regional maybe) of Grasylda which comes from the name
Griselda. There isn't a single Grasyla in the national registry and it has everyone alive since 1992 so presumably the last Grasyla died before then. The one in my family tree was born probably around 1870ish.
My great aunt Zygfryda also had an interesting and rare name.
Tekla is maybe less interesting but also rare (at least nowadays) and very pretty.
https://www.behindthename.com/pnl/109883