The absurd amount of card advantage that Necro offers, essentially allowing you to convert life into cards, makes it one of the strongest card-draw spells that has ever been made
Another benefit is that you can spend five mana to give all of your Creatures lifelink
Its way too situational to be useful and it also has quite a bit of rules baggage, so it should be used sparingly
Whether it's Waterbending Scroll , from the recent Avatar set, encouraging players to go mono blue, or Mechtitan Core from Kamigawa Neon Dynasty turning into a 10/10 Gundam if enough artifacts are stapled onto it
Just looking at a few of my own decks, I dont run it in Joshua, Phoenixs Dominant Reanimator/Flicker, preferring instead to stick to making my land drops and reanimating lands out of the graveyard with Redemption Choir and Sun Titan
Primal Genesis The Naya identity deck from Commander 2019, Primal Genesis, is admittedly my blindspot