The idea behind this deck is everyone loves playing expensive spells with destroying effects, and Cruel Ultimatum is one of th best spell to do so; it forces your opponent to sacrifice a creature, which can deal with big fatties, makes them dump their hands, ping them for 5, and you get the exact opposite.
Gabriel Nassif, who is one of my favourite players of all time played a 5 color control deck in Alara, which eventually won PT Kyoto 2009 with a great final against LSV. The deck was deemed possible thanks to a manabase relying on Reflecting pool and vivid lands.
In modern however, the vivid land package is too slow, we have to work with fetchlands / shocklands and lands from battle for zendikar.
It started out as a Grixis Cruel Control deck, but the addition of Abrupt decay and Broodmate Dragon made the deck even better. In term of value, bringing back a broodmate dragon is really good. That meant splashing green, which is why the manabase is still work in progress. Tasigur made a good addition, being an extremely good body, with a nice ability. Fatal push was included to deal with Goyf and Bob.
The strategy is to slow down your opponent using counterspells / diruption / Removal, until like turn 4/5, cast a Tasigur, then try to get to 7 mana. To keep your hand full, you have Cryptic command, and Mulldrifter. It is excellent in the deck. Play it with evoke to fill your hand, and bring it back with Cruel Ultimatum. a 2/2 Flyer is still relevant to finish someone.
The next step is to try to fix the mana, test multiple combinations of spells ( maybe replacing broodmate dragon with something else...) and improving sideboard.
The deck is bad against Tron, so Fulminator mage might be a good addition.
Against mono red, I had good games, as long as you are able to kill gobling guide fast.
Againt control it is ok most of the times.
If you like the deck, or think of ideas, don't hesitate to comment.
I don't exclude colors for splash, and am interested in any suggestion.
Thank you for reading.
-2 smoldering marsh
+2 overgrown tomb
-1 watery grave
-1 steam vents
+1 misty rainforest
+1 bloodstained mire
