Having played Wilde Jagd, I voted for Friska. Wilde Jagd sounds impressive but it is seriously not that hard, I'd say it's the easiest of the virtuosic sounding Transcendental Etudes. A lot of it lies comfortably under the hands, and the trickier parts with jumps you just need to practice slowly and carefully and you'll hit at least 90% of the notes when performing
The flats in the key makes it way more forgiving.
Honestly, (keep in mind that I haven't even tried any of the etudes except Preludio) I feel like Wilde Jagd is capable of challenging Chasse-Neige for the 3rd hardest of the transcendentals. The three-fingered trills in the right hand near the end at the same time as multi-octave jumps are nigh impossible. The arpeggios in the cadenza, the leaps often spanning multiple octaves, the desynced hands throughout the song (for example, right at the start), and the fact that it comes in at just under 5 minutes only add to the difficulty. Friska has a lot of leaps and repeated notes with a few runs and trills thrown in, but it is much shorter and, imo, less difficult overall.
Nowhere near Mazeppa though.