"Take 59 Flights of Stairs" isn't a real Magic keyword—it's a reference to the Un-set style joke or a meme rather than anything in the comprehensive rules. There's no official ability by this name in any sanctioned or silver-bordered set, so it has no defined gameplay function.
If you encountered it in casual play, it's likely a custom card, a homebrew effect, or someone's inside joke. In that case, the table needs to agree on what it actually does before resolving it, since there's no rulebook backing to reference.
For real Commander games, stick to officially printed keywords. If you saw this somewhere specific—a particular card image or set—double-check the source, because it's almost certainly fan-made or satirical rather than tournament-legal.