For one, it's very compact, and we have seen it in a variety of decks including 4C Gifts (which is enjoying great MTGO success with about 2% of the online metagame), UW Tron, UWR Gifts, Esper Gifts, and a few other fringe strategies
So you're encouraged to play cards that cost 3 or more, and it's a complicated puzzle to balance with creatures to target, high quality spells that target, and have the ramp to do them
Advanced Search Sets Random Syntax Aberrant Argothian Enchantress Ashiok's Reaper Astral Drift Bello, Bard of the Brambles Bucket List (playtest) Chakra Meditation Champions from Beyond Charitable Levy Communal Brewing Confounding Conundrum Corruption of Towashi Creepy Crawler (playtest) Decree of Silence Demonic Covenant Disinformation Campaign Dovin's Acuity Eidolon of Blossoms Ellivere of the Wild Court Enchantress's Presence Enduring Curiosity Enduring Innocence Entity Tracker Ephara, Ever-Sheltering Extraordinary Journey Femeref Enchantress Firemind's Research Fleeting Memories Freyalise's Charm Frostcliff Siege Fugitive Druid Garruk's Uprising Glissa Sunslayer Guild Summit Hollowmurk Siege Hoofprints of the Stag Ineffable Blessing Ineffable Blessing Ineffable Blessing Ineffable Blessing Ineffable Blessing Ineffable Blessing Intimidation Campaign Invasion Tactics Kestia, the Cultivator Killian, Decisive Mentor Kindred Discovery Lost Isle Calling Mesa Enchantress Mirrodin Besieged Narci, Fable Singer Niko Aris Oath of Lim-Dl Obsessive Pursuit Ominous Seas Pearl-Ear, Imperial Advisor Phenomenon Investigators Political Triumph Quint's Insight Rewrite History Rite of Harmony Robot Domination Satyr Enchanter Setessan Champion Shadow of the Goblin Shoal Kraken Sigarda's Splendor Sparring Regimen Stocking the Pantry Struggle for Project Purity Sythis, Harvest's Hand Tameshi, Reality Architect
And at what point do you start to look at other delve possibilities
