Exile, Prosper v1 (EDH / Commander)

Prosper, Tome-Bound is the primary cog in a cast-from-exile, impulse draw engine that slings spells, subsidized by treasure generation & multiplication. Versatile win-cons via artifact-pumped beaters (Storm-Kiln Artist, Laelia, the Blade Reforged, Urza's Saga), Direct damage (Marionette Master, Nadier's Nightblade) or Revel in Riches, perhaps accelerated by Gonti's Aether Heart.

Creatures/Planeswalkers - Impulse draw + treasure triggers.

Storm-Kiln Artist - Generates a treasure for each instant, sorcery or copy. Each artifact (treasure) adds a +1/0 to it for some huge swings.
Birgi, God of Storytelling // Harnfel, Horn of Bounty - Horn side provides obvious impulse draw value < Casting spells w/ Birgi in play offers 1 mana back each, fueling big turns.
Xorn - Any treasure gaining event happens at +1. Prosper's right hand.
Laelia, the Blade Reforged - Exile trigger on attack, gains a +1/+1 counter from it's own ability or any card you send to exile from library or grave - which happens a lot. Big swings.
Goldspan Dragon - Creates treasure, doubles treasure payoff.
Tibalt, Cosmic Impostor - +2 loyalty to exile a card from each library, -3 to target exile, -8 to exile all graves and you can cast any of these, whenever. And get paid to do it. Insane.
Murderous Rider // Swift End - Removal, then cast Rider from exile for trigger.
Wild-Magic Sorcerer - 1st spell cast from exile each turn has cascade (+ extra trigger).
Chandra, Fire Artisan - +1: impulse 1, -7: impulse 7.
Chandra, Torch of Defiance - +1: impulse 1, play or deal 2 dmg.
Opposition Agent - Exile the results of opponent tutors, cast any time.

Tools + treasure triggers

Jeska's Will - Impulse draw x3 + mana to use it. Extra spicy with Prosper.
Valakut Exploration, Stolen Strategy, Theater of Horrors, Outpost Siege - Each adds additional impulse draw options per turn with simple conditions. Valakut is lowest to ground and probably best as a result.
Share the Spoils - Once per turn, everyone may chose and cast one from cards exiled from the top of each library - but only you get paid for it and most of your spells won't hold the same appeal without Prosper on their side.
Light Up the Stage - Value impulse. Dry tinder to ignite big turns.
Volcanic Torrent - Cascade (exile trigger payoff) + 'Storm' damage. Removal, free spell and treasure. Great in Prosper.
Throes of Chaos - Recurring cascade trigger from the graveyard - never a wasted turn.
Creative Technique - Pseudo-cascade w/ no upper limit. Copiable and repeatable.
Fevered Suspicion - Exile 1 from each library, play without playing, Rebound.
Blood Money - Board wipe, each non-token creature = 1 treasure.

Win-cons

Apex of Power - You will have the mana to use this ahead of curve. Exile 7 cards to cast and +10 mana. Keep in mind, those 7 cards also pay you a treasure each when cast with Prosper out in play.
Marionette Master - Deals it's power in dmg to target op upon each of your artifacts to graveyard (treasures).
Revel in Riches - Create a treasure when any creature dies. Owning 10 treasure at Upkeep = win.

Other Notes:

Uba Mask - All card draw becomes same-turn impulse draw. Plays into your strategy and throws off everyone else.
Urza's Saga - Turn 2, create X/X construct, where X is = to # of artifacts (treasure). Turn 3, go get mox or sol ring.
Reverberate and/or Fork - Offence and Defense. Double a big play or copy and counter a counter spell to protect it.
Treasure Vault - In conjunction w/ Revel in Riches - crack it before your upkeep to top up win-con.

2 player vs multi-player tweaks:

For multi-player play, remove Rite of Flame or least favorite mana-rock to add Shiny Impetus.