Legacy Conflux deck
Conflux is a Legacy combo deck utilizing Dream Halls to play a large quantity of damaging spells. The namesake card is used to gain a large amount of card advantage and quality and the deck thrives on the interaction that Conflux can be played off Dream Halls by pitching any card as well as Conflux being possible to be pitched to play any card.
Ideally the deck starts off with an Island (or a fetch land into an Island) and Brainstorm. The next turn the deck plays Ancient Tomb and casts Show and Tell to put Dream Halls into play. Then the deck discards any card to play Conflux. The Conflux fetches two or three more copies of Conflux, a Bogardan Hellkite and Progenitus. Another Conflux is played by discarding Progenitus (shuffling him into the library) which searches for a number of copies of Progenitus and all copies of Cruel Ultimatum. Then the Hellkite is discarded to cast Cruel Ultimatum which in turn deals 5 damage to the opponent and returns the Hellkite to hand. This is repeated for each copy of Ultimatum and finally the Hellkite is also played by discarding another multicolored card such as Progenitus or Conflux. With at least 3 copies of Ultimatum and one Bogardan Hellkite, each dealing 5 damage, 20 damage is dealt to the opponent.
An alternate gameplan involves simply dropping Progenitus with the Show and Tell and repeatedly attacking the opponent with the unblockable and virtually unkillable creature.