Yahenni's Expertise

Oracle Text
All creatures get -3/-3 until end of turn.
You may cast a card with converted mana cost 3 or less from your hand without paying its mana cost.
Card Rulings
2/9/2017 If a creature’s toughness is reduced to 0 or less by Yahenni’s Expertise, that creature is still on the battlefield as you cast your free spell. It can be the target of that spell, although it will become an illegal target before that spell resolves. If it has any abilities that trigger on the spell being cast, those abilities will trigger.
2/9/2017 A card’s converted mana cost is determined solely by the mana symbols printed in its upper right corner. The converted mana cost is the total amount of mana in that cost, regardless of color. For example, a card with mana cost has converted mana cost 3. Ignore any alternative costs, additional costs, cost increases, or cost reductions that could apply to it. A card with no mana cost has a converted mana cost of 0.
2/9/2017 If the card has in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
2/9/2017 Effects that allow you to “cast” a card don’t allow you to play a land card.
2/9/2017 If you cast a card “without paying its mana cost,” you can’t choose to cast it for any alternative costs, such as emerge costs. You can, however, pay additional costs. If the card has any mandatory additional costs, such as that of Cathartic Reunion, you must pay those to cast the card.
2/9/2017 While you’re casting your free spell, the Expertise spell is still on the stack. It will be put into its owner’s graveyard after the free spell is cast. The free spell can’t target the Expertise card in your graveyard. It can target the Expertise spell on the stack, but the Expertise spell will become an illegal target before the free spell resolves.
2/9/2017 Any triggered abilities that trigger while performing the Expertise spell’s first effect won’t be put onto the stack until after you’re done casting your free spell. They’re put onto the stack at the same time as any abilities that triggered while casting that spell regardless of the order in which those abilities triggered.
4/18/2017 The converted mana cost of a split card is determined by the combined mana cost of its two halves. If an expertise spell allows you to cast a split card, you may cast either half or, if that split card has fuse, both halves.
This is going to kill all my Merfolk, then slap me in the face with a free Abrupt Decay on my Aether Vial.
The goal is fun interactions. Bringing back a mechanic, does not require them to print cards that are broken.
4x City of Brass
3x Forbidden Orchard
4x Gemstone Mine
4x Mana Confluence
2x Reflecting Pool
2x Swamp
2x Tendo Ice Bridge
Creature (13)
4x Borborygmos Enraged
4x Griselbrand
1x Iona, Shield of Emeria
4x Simian Spirit Guide
4x Dismember
4x Soul Spike
2x Thirst for Knowledge
4x Violent Outburst
Sorcery (12)
4x Breaking / Entering
4x Demonic Dread
1x Unburial Rites
3x Yahenni's Expertise
2x Boseiju, Who Shelters All
1x Goblin Dark-Dwellers
2x Ingot Chewer
4x Leyline of Sanctity
3x Not of This World
1x Shatterstorm
2x Wispmare
It works by using 8 cascade spells in combo with the split card : Breaking / Entering. When you cascade into this card, you can choose to play either side of it without paying its mana cost! (Breaking is a 2 CMC spell). This means that if you fill your deck with cascade cards, and Breaking / Entering is the only possible target that is lower then 3 cmc, you can cascade through the deck and find Breaking / Entering, then cheat on the mana cost of either side ( including Entering) to return huge creatures to the battlefield!
Here is an example of how the deck would play out :
A) Cast the Breaking side of Breaking / Entering either by drawing it, by cascading into it, or using Yahenni's Expertise to play it from your hand.Then mill the top 8 cards from your library into your graveyard. (Usually putting a creature card or 2 into your graveyard).
B) Cast Entering side of Breaking / Entering by cascading into it or by using Yahenni's Expertise.. Reanimate one of the creatures in your graveyard.. Use that creature to win the game!
c) Cast Thirst for Knowledge at end of your opponent's turn and discard two creatures from your hand to your graveyard. On your turn use either Violent Outburst , Demonic Dread, Unburial Rites or Yahenni's Expertise and re-animate the creature you discarded!
Tappedout link to deck : http://tappedout.net/mtg-decks/violent-reanimator-1/