Legacy Curses deck
UPDATED MARCH/2022
Curses is a deck that focuses on Curse-type enchantments to lock the opponent out of the game. The main Curses deck is found in Mono-Black, while Curse-based strategies are also found in Nic Fit decks. It is a Control/Prison strategy.
Overview
It is uncertain to say precisely how the Curses archetype came to be.
Unlike many of its Legacy peers, the Curses deck archetype appear to be more recent.
Browsing the MTGTop8 Deck Search history, everything seems to indicate the first curses were used in Legacy inside a Nic Fit build.
The earliest Nic Fit strategy documented in the site's database dates from 2011. And the first recordings of the usage of Curse cards from today's Curse decks are from 2016's Nic Fit decks.
The 2016's deck featured a single Curse: Curse of Death's Hold. But, by 2017, the deck featured Overwhelming Splendor, Curse of Death's Hold, Curse of Misfortunes and Curse of Predation.
The way both the Curses deck and the Nic Fit deck share (even today, sometimes) a number of Curse-type cards seem to indicate the current Curses deck evolved naturally from the Nic Fit strategy. And, after this, the Curse-based strategy also looks to have branched into Nic Fit decks and Curses decks.
The first deck called Curses registered in the Legacy format in MTGTop8 is from 2020 and was made in a Mono-Black shell.
This is the first deck found with the usage of Curse-type cards in a Nic Fit in MTGTop8 from a deck in 2016:
Nic Fit employing the Curses strategy
This is an example of a Nic Fit deck wielding the Curse strategy.
Contemporary Decklists
And this is the actual curse deck in a Mono-Black control shell.
It benefits from Urza's Saga and it may tutor for Vault of Whispers and Retrofitter Foundry.
It also implements a Karn-based toolbox with Karn, the Great Creator which even synergizes with the alternate win-condition of Helm of Obedience + Leyline of the Void.
The Karn toolbox gives access to boardwipe with Sphere of Annihilation, a "silver bullet" with Pithing Needle, defense against aggro with Ensnaring Bridge and various shenanigans: Torpor Orb, Liquimetal Coating, Vault of Whispers, Mycosynth Lattice.