It made a big splash because it forces your opponents to make difficult decisions about providing you ramp in the form of Treasure tokens any time they draw a card
A Whole New World is also great against discard decks that try to bleed you out of resources quickly
What Makes a Chase Card in Ascended Heroes

WHITE | BLUE | BLACK | RED | GREEN MULTICOLORED | ARTIFACT | LAND | ALL CARDS WHITE Coppercoat Vanguard Deification Harnessed Snubhorn Metropolis Reformer Spark Rupture Tazri, Stalwart Survivor BLUE Filter Out Tolarian Contempt Training Grounds Vesuvan Drifter BLACK Ayara's Oathsworn Blot Out Death-Rattle Oni Markov Baron Urborg Scavengers RED Arni Metalbrow Kolaghan Warmonger Plargg and Nassari Reckless Handling GREEN Animist's Might Leyline Immersion Nissa, Resurgent Animist Open the Way Tranquil Frillback Undercity Upheaval MULTICOLORED Calix, Guided by Fate Campus Renovation Cosmic Rebirth Danitha, New Benalia's Light Feast of the Victorious Dead Gold-Forged Thopteryx Jirina, Dauntless General Jolrael, Voice of Zhalfir The Kenriths' Royal Funeral Kiora, Sovereign of the Deep Nahiri, Forged in Fury Nahiri's Resolve Narset, Enlightened Exile Nashi, Moon's Legacy Niv-Mizzet, Supreme Ob Nixilis, Captive Kingpin Pia Nalaar, Consul of Revival Rebuild the City Rocco, Street Chef Samut, Vizier of Naktamun Sarkhan, Soul Aflame Sigarda, Font of Blessings Tyvar the Bellicose ARTIFACT Karn, Legacy Reforged LAND Drannith Ruins WHITE | BLUE | BLACK | RED | GREEN MULTICOLORED | ARTIFACT | LAND | ALL CARDS

At PAX Prime, Wizards opened the door to Duskmourn and kicked off its preview season with a look at the art treatments and mechanics well encounter when it launches on September 27
So, lets dive into what these Secret Lair drops contain and what the most sought-after cards are within the events many drops