Boomerang Basics From the Avatar: The Last Airbender set, we get a card that speaks to my combo-loving heart
With Doubling Season, Jace enters with double counters and can create self-copies right away
At 2+, it needs to work) Black Slaughter Pact Dismember Thoughtseize Darkblast Curse of Death's Hold Honorable mention: Sudden Death It's a trap!: Liliana of the Veil (Typically counted as removal by decks that use her

Orfeo, the Boulder Nimble Larcenist Obscura Ascendancy Obscura Charm Obscura Interceptor Ognis, the Dragon's Lash Queza, Augur of Agonies Raffine, Scheming Seer Rakish Revelers Rigo, Streetwise Mentor Riveteers Ascendancy Riveteers Charm Rocco, Cabaretti Caterer Shattered Seraph Soul of Emancipation Spara's Adjudicators Toluz, Clever Conductor Unleash the Inferno Void Rend Ziatora, the Incinerator Ziatora's Envoy Ob Nixilis, the Adversary Scheming Fence Brazen Upstart Brokers Ascendancy Brokers Charm Cabaretti Ascendancy Cabaretti Charm Cormela, Glamour Thief Corpse Appraiser Crew Captain Disciplined Duelist Endless Detour Evelyn, the Covetous Falco Spara, Pactweaver Fleetfoot Dancer Glamorous Outlaw Hostile Takeover Incandescent Aria Jetmir, Nexus of Revels Jinnie Fay, Jetmir's Second Lagrella, the Magpie Lord Xander, the Collector Maestros Ascendancy Maestros Charm Maestros Diabolist Masked Bandits Mr
Then include answers to those exact things
With multiple potential effects to choose from, with enough black mana Doomsday Confluence can build up your board, destroy your opponents board presence, and send their hands right to the grave, effectively locking them out of the game in one fell swoop