Wings of mercy for Preforming Azura?

No, it's not worth it. Give her axe breaker 3 if you can.

Wings of Mercy is great on her, but I would just wait for a Cain. Axebreaker is a good filler that synergizes with Triangle Adept

Escape Route 3 could serve as a temprary place holder to WoM but definitely dont spend 20,000 feathers for WoM

What they said re Axebreaker, which you can get from a 4* Laslow.

I gave mine WoM 3 back when I pulled her on the Performing Arts banner and have never regretted it. Once my Brave Lyn and Rein get into WoM range they easily solo TT alone and pretty much any map.

Wing of Mercy 3 really shines when you have multiple units in range of its threshold, especially if they use something like Desperation (Ayra) and the likes.