Thousand-Year Elixir lets you tap creatures to use their abilities even when they have summoning sickness as if they have haste
You also need one clean answer wipe so you do not lose to indestructible or recursion loops
Ruinous Intrusion Instant speed artifact or enchantment removal with upside can be great
With one of the best anime alt-arts seen so far in MTG, this card is likely to remain in Ravnica Remastereds top spot for some time yet

Legacy Meta and Decks Dimir Reanimator Reanimate | Illustration by Nils Hamm Creatures (17) Abhorrent Oculus x2 Archon of Cruelty x2 Atraxa, Grand Unifier Griselbrand Metamorphosis Fanatic x2 Murktide Regent x2 Psychic Frog x4 Tamiyo, Inquisitive Student x3 Instants (13) Brainstorm x4 Daze x3 Fatal Push x2 Force of Will x4 Sorceries (15) Careful Study x4 Ponder x4 Reanimate x4 Thoughtseize x3 Enchantments (2) Animate Dead x2 Lands (17) Flooded Strand Island Polluted Delta x4 Scalding Tarn Swamp Undercity Sewers Underground Sea x4 Wasteland x4 Sideboard (15) Barrowgoyf x2 Brazen Borrower x2 Consign to Memory x4 Fatal Push x2 Ghost Vacuum Go for the Throat Null Rod x2 Unlicensed Hearse You can expect to see plenty of blue-black, Dimir Reanimator in Legacy matchups, so do you have a way to stop Tamiyo, Inquisitive Student, Reanimate, and Metamorphosis Fanatic
Do be careful, because this land doesnt help to protect spells already on the stack