The extra card in play boosters has a chance of being a token, marketing card, or art card
Necropotence with Dark Ritual was a defining feature of the format and very difficult to stop without the full suite of turn-1 free countermagic available to Magic as a whole
The ability to instantly swing a match through a zero-cost shift makes it a mandatory inclusion for elite competitive decks
It is rather bizarre that it's not a creature as the card's sole focus and name is on Shahrazad (or Sheherazade), a character from the 1001 Arabian Nights story, but that's not even the least of why this card is so iconic
In a 1v1 match it might be more balanced like the Tui and La depict, but at a 4-player commander table, it's usually quite worth it for you to pay the cumulative upkeep for a couple of turns
Those lines are potential trades that have a chance to be very profitable for you