Youll typically pair Narset with extra turns and combats so your opponents never have another turn

Advanced Search Sets Random Syntax Abhorrent Overlord Abyssal Harvester Abyssal Persecutor Ammit Eternal Apocalypse Demon Arbiter of Woe Archdemon of Greed Archdemon of Paliano Archdemon of Unx Archfiend of Depravity Archfiend of Despair Archfiend of Ifnir Archfiend of Sorrows Archfiend of Spite Archfiend of the Dross Awoken Demon Baleful Ammit Balor Be'lakor, the Dark Master Blade of the Oni Bloodcrusher of Khorne Bloodgift Demon Bloodletter of Aclazotz Bloodthirster Bone-Cairn Butcher Bothersome Quasit Bringer of the Last Gift Burning-Rune Demon Butcher of the Horde Carnifex Demon Chaos Defiler Chaos, the Endless Conductor of Cacophony Crabomination Daemogoth Titan Daemogoth Woe-Eater Death-Rattle Oni Defiler of Souls Defiling Daemogoth Demon Wall Demon of Catastrophes Demon of Dark Schemes Demon of Death's Gate Demon of Fate's Design Demon of Loathing Demon of Wailing Agonies Demonic Covenant Demonic Hordes Demonic Taskmaster Demonlord Belzenlok Demonlord of Ashmouth Desecration Demon Doom Whisperer Doomsday Excruciator Dread Cacodemon Dreadfeast Demon Dreadhound Dream Devourer Eater of Hope Embodiment of Agonies Enemy of Enlightenment Etched Host Doombringer Exalted Flamer of Tzeentch Extractor Demon Falco Spara, Pactweaver Feaster of Fools Fiendish Panda Frenzied Raider Goremand Great Unclean One Grinning Demon Griselbrand

You can only chose a given option once a turn, but it's not restricted to your turn, so a timely Auroral Procession or Unbury can create a surprise blocker or extra card advantage
Instead of being stuck, you can pay three generic mana, discard the Triome, and draw a new card
Sorry, but the FF set was pretty overpowered and thus this list needed to be longer too!
The same is true if an opponent's permanent gains indestructible or hexproof after The Fire Nation Drill's ability resolves