Free Scourging PAU (Pauper)

A fast combo deck based on the interaction between Undercity Scrounger and Freed from Real. The basic "combo" is enchanting Undercity Scrounger with Freed from Real, have a creature die, and have a Disciple of the Vault on the field. Once those conditions are true, you can tap the Undercity Scrounger to generate a treaure token, sacrifice it (making an opponent lose 1 life) to add a blue mana, use Freed from Real to untap the Undercity Scrounger, and repeat the process, causing a arbitrarily large life loss.
The problem of the combo is twofold: it's relatively frail (it's based on two creatures, one of which is a 1/1), and it's difficult to tutor for (being composed of two creatures and a enchantment of different costs). An alternative to Disciple of the Vault is Salivating Gremlins - they're a hardier creature (2/3 instead of 1/1) and they cost 3, which makes the whole combo tutorable with Dift of Phantasms/Perplex... but at the same time this change makes the deck weaker, as now you're in three colours.
The deck in itself, apart from the combo, it's mostly based on recycling stuff, drawing, and controlling. You have some spot removal - Cast Down - but mainly you aim to draw a lot to get the combo asap. And drawing is something the deck does exceedingly well, since it has Deadly Dispute, Reckoner Bargain, Blood Fountain, Myr Retriever and Ichor Wellspring, all cards that lets you draw massive amounts of cards.
The ideal hand is one with the three combo pieces and some spot removal. You could go Disciple T1, Cast down T2, Undercity Informer T3, and then Viscera Seer+Freed from Real T4, sacrificing the Seer to its own ability to start the combo.
Of course the whole thing is highly experimental.

Some ideas to be expanded upon:

• Dropping the combo to 1x, using Salivating Gremling instead of Disciple of the Vault. Adding Perplex/Drift of Phantasms. (More control over the combo pieces, less sustain and speed. Also, it adds a third color.)
• Less draw, more removal, especially board removal (Crypt Rats). (More control, less draw)
• Dropping the artifact package and instead using Mnemonic Wall + Death Denied (The whole instant package now is recurrable, but it's slightly slower)
• Fitting the combo as 1x in a Tron shell with a Mystical Teaching -> Perplex tutoring package (Very unreliable without mana fixing)

EDIT: No longer pauper legal after Disciple of the Vault banning.
EDIT: Now legal again - instead of using Disciple of the Vault, Gixian Infiltrator is being used. It's still frail but it offers a similar synergy while not adding a third colour.