Charles-Valentin Alkan's '3 Morceaux dans le Genre pathétique' Op.15 are notoriously difficult etudes that explore extreme pianistic challenges. They are characterized by their dramatic intensity and virtuosic demands.
The primary challenge lies in mastering the extreme stretches and rapid figuration required for each piece.
3 Morceaux dans le Genre pathétique (Op.15) is rated Henle level 9 of 9 — virtuoso repertoire, roughly concert / virtuoso level. In the RCM system it corresponds to about level 9.
You should be comfortable at Henle level 9 — meaning you can already play level 8–9 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
3 Morceaux dans le Genre pathétique (Op.15) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.