Dark Petition
+
Raven's Crime
+
Spellweaver Helix
The idea is pretty simple: play Dark Petition with Spell Mastery active; find
Spellweaver Helix
, and play it using the the BBB; exile Raven's Crime and Dark Petition; now every Raven's Crime you play replaces itself with a land, nets two extra mana, and eventually even searches up the Exsanguinate or Emrakul, the Aeons Torn you need to end the game. All in a neat little bundle.
Combo doesn't actually take a lot of space, so it can slide pretty easily into a super-disruptive frame: really only needs one Helix (which might not be terrible in a discard heavy deck anyway) and one Petition (but it's a combo piece that finds your other combo pieces, so why not?), one finisher, and there are decks that already run several Raven's Crime main.
The one problem is that the deck obviously only goes off once: once the lands are out of your deck, they're gone. There are easy ways to restock them (Emrakul helps out there) if that's a concern, and in a deck that searches as part of the combo those shouldn't be hard to find. Dakmor Salvage would probably be the first lands you grab, which combos with Raven's Crime all on its own; at that point, something like Sign in Blood fetches you two lands on its own, which frees you up to use the next search for something else.
Graveyard hate is also a problem, so I'd consider splashing some other color to avoid that. Blue seems the best option as it offers more disruption, and can remove troublesome enchantments (Leyline of the Void, Rest in Peace) for the turn while you go off, but more than anything because it protects the combo the best (though I suppose actually paying for Pact of Negation shouldn't be relevant often). Might consider White instead, simply for efficient, permanent answers; Green can answer the enchantments, and also provides a Plan B of just ramping into Emrakul.
Obviously just plopping out ideas at the moment. I'm a huge fan of janky combos, but I remember loving how Tooth and Nail didn't feel janky simply because the 'combo' just found all its own pieces. Just trying to achieve the same thing a little more reliably here.
