all battle cards mtg MTG: March Of The Machine Expansion Previews New And Mechanics Destroy target permanent an opponent controls. Battle - MTG Wiki

These are commonly corrected in an official errata and when reprinted are given the correct text

Now think about paying seven life for 7/7s, a kill within three turns, or even 10/10s to kill with just two hits

To unpack it in simple terms, this Grixis (Red, Blue and Black) creature has the ability to copy instant or sorcery spells that target just one player or permanent and use the new copies so that every player at the table (except you) gets hit instead

Combine this with other powerful cards like Portable Hole, and you have a winning strategy

rather as a legendary creature token

Jack-in-the-Mox is a reference to the Mox series of cards, but is otherwise not as interesting other than, again, the usage of dice, which is unconventional for sure but nowhere that funny