Living End can attack certain metagames such that your opponents will have no chance of winning. You can load up your graveyard with creatures thanks to cycling, and Amonkhet has given us even better options to bring back. Because all of these spells draw deeper into your deck, you can fight against some amount of graveyard hate, and you can even hardcast your overpriced creatures in desperate times!
Living End is a suspend card that is rarely suspended. Instead, you load up your graveyard by cycling or sacrificing, then cast a cascade spell. As long as you don’t have any cards in your deck that cost fewer than 3 mana, every cascade spell is guaranteed to hit a Living End. Not only do you get back a bunch of large creatures from your own graveyard, but you get to sweep your opponent’s board too. When common graveyard interaction hate cards like Grafdigger’s Cage don’t even have an effect on your deck, you’ve got something special.
Violent Outburst is your key cascade spell. You can cast it at instant speed to resolve a Living End during an opponent’s end step or in response to a spell. You also don’t have any restrictions on casting it, unlike Demonic Dread. Dread does need a target and can only be played at sorcery speed, but a 3-mana Living Death is still just that good.
Desert Cerodon and Horror of the Broken Lands added a pair of 1-mana cycling creatures to an already powerful deck. Both of these creatures can easily attack for 6+ damage, so you have lots of ways to close out the game in a single turn even early on. With more imposing creatures that only cost a single mana to cycle in the deck, you can use your mana more efficiently to find what you need.
Monstrous Carabid is the best 1-mana cycling creature you still get to run a full playset of. A hybrid mana cycling cost helps to make sure you don’t stumble. Street Wraith is still as broken as ever, since a 0-mana cycling creature (that often has evasion) is ridiculous.
Archfiend of Ifnir gives you another great cycling option that can sweep the board of opposing chump blockers. A flying threat that fights small creatures effectively is a welcome addition.
Fulminator Mage allows Living End to play a disruptive plan and make sure that big mana decks can’t get ahead. While Violent Outburst lets you play a Living End at instant speed to play around some sorcery-speed sweepers, you have a limited number that you can play (and only 3 copies of Living End to find), so this can be a weakness of the deck. Fulminator Mage destroying a land and then destroying another when Living End resolves keeps your opponents from going over the top of you.
Beast Within gives you additional disruption. It’s a great way to continue the land destruction plan or to kill something like Rest in Peace or Leyline of the Void. You can even clean up the Beast token with Living End!
Faerie Macabre gives you another card that can enter the graveyard for free, but more importantly it can clear tough creatures out of opposing graveyards so that they don’t also return from Living End. There’s also some added utility in the mirror, against Dredge, and to stop a Snapcaster Mage that would have ruined your day with a counter.
Simian Spirit Guide is awesome in so many decks, but the extra mana to make sure you can resolve your spells a turn early (or get on the early land destruction plan) is a nice bonus. You’re playing a mana-light deck, so getting to 3 helps when the cyclers aren’t getting there.
Another sweet addition to this deck is in Kari Zev’s Expertise. While stealing a creature can be nice, and you may be able to take a blocker to swing for the win, it’s also a way to cast a Living End from your hand. Opponents will rarely target Living Ends in hand with discard spells since they can’t be cast, and suspending is usually miserable. The Expertise gives you a potential game-changing Living End when you would otherwise be in real trouble.
Living End is a strong Modern deck that has picked up a ton of new weapons to allow you to play an even more powerful and consistent game.