LEAVE MODERN ALONE, SHE'S ALREADY SUFFERED SO MUCH alternate title "those who fight monsters" alternate title "this deck originally had 4 rest in peace mainboard to hate out lingering souls and tasigur because I hate Abzan that much"
Okay so serious description let's go This is a traditional control deck with 0 win conditions (except theoretically Lingering Souls) until turn 8 with an active Celestial Colonnade and some mana up, using Gifts Ungiven
+
Noxious Revival
to force your opponent to give you either a direct answer or something awful. There's enough singletons to ensure you always have 2 answers and a Noxious Revival to gifts for, and in a pinch you can add in Snapcaster Mage to flashback Revival to ENSURE you get whatever answer you need. If you don't need anything specific, you can always go for Cryptic Command, Sphinx's Revelation, lands, and more Gifts Ungiven to ensure you always have a full hand to deal with threats. Remember that
Hallowed Burial
is a permanent answer to Finks and other such obnoxious threats. Phantasmal Image can copy Siege Rhino, Tasigur, the Golden Fang, and
Wilt-Leaf Liege
and not only get value, but also be immune to Abrupt Decay. Copying a Tarmogoyf isn't bad, either. May not be relevant in all matchups, but this deck is built for Abzan.
Consuming Vapors
is great to help quickly stabilize against an overextended Abzan player, too, but can also catch many other decks off guard. Castigate is less painful than Thoughtseize against burn and kills Lingering Souls nice and dead.
The sideboard is modular, with options for each and every matchup; Disenchant is great against Twin and all the other Blood Moon-type decks, Disenchant, Pithing Needle and Phyrexian Revoker along with Path to Exile and Timely Reinforcements helps dull Affinity if necessary, those last two holding great against Burn, Tectonic Edge and Dispel makes control mirrors less rough, and if you find you need more gas in any matchup, or don't know what to side in while siding out irrelevant spells, more Sphinx's Revelations are always nice.
In a less disruptive, more fringe meta, an
Unburial Rites
package (main or side) for the Gifts Ungiven + Unburial Rites
combo can solve many of the odd, nonstandard decks in the format, whereas a suite of Path to Exile and Murderous Cut has your back if you face a lot of manland-bearing control or aggressive shells, or otherwise need a lot of single-target removal for some reason.
Torpor Orb is a good grab for Twin, turning off the Twin combo entirely with support spells like Spell Snare and Spell Pierce there to dull the tempo aspect of the deck.