It is written for overseas card shops, online sellers, breakers, convention vendors, and collector-resellers buying Japanese inventory from Tokyo
If your deck happens to be playing Eternal Scourge, Misthollow Griffin, Torrent Elemental, or Squee, the Immortal, you might consider Altar of Bhaal if black is in your color identity
None of this is likely better than Wilhelt, the Rotcleaver, but this zombie warlock might be a nice way to power down that deck while still giving you fun things to do, if thats on your radar
While this is all very mysterious so far, thankfully the sets product page reveals more information about what to expect
If the chosen target is illegal when Lightning Helix tries to resolve, it won't resolve and none of its effects will happen