This is my UB mill deck and i find it offensive that you aren't already playing with it.
--Shelldock isle--The most, if not, one of the most challenging things about this deck, hideaway the righ card.You need to think about what your oponent can't and can do, mostly you want to hideaway your undead alchemist to get rid of all those pesky eldrazis, or maybe a jace to get it out there for free, any of the cards you decide to pick i really recomend you never, EVER, pick a control card, you need all of them in your deck, also if you have a fetchland in your hand i strongly recomend to save it after this so you can shuffle away your deck if it were some nice cards so they don't get bored on the bottom of your library.
--Archive Trap--The best milling card in the entire game for now.
--Boomerang--Just for some quick control convined with mana leak, or alternatively you can throw away away your undead alchemist if your 2/2 zombie tokens can do letal damage to your oponent this turn.
--Milling Cards--The best out there, no need for more, need for best. Milling needs powerfull cards that can either get completly crazy or be constant permitting you still control de flow of the game wiouth sacrificing your milling. Still, the need of better milling cards is clear, either instant milling cards or more powerfull ones.
--Creatures--Undead Alchemist = Exponencially growth in milling/Chunk blocking tokens/Exile monsters preventing them from entering the graveyard.
Hedron Crab = little bit of chunk blocking and a nice milling with the landfall, 2 hedron crabs + a fetchlands = 12 milled cards ;)
Snapcaster Mage = OHHH SNAP!
--Jace Memory Adept--DUHHH! really, 70% of milling decks needs him, is just so usefull and he takes a lot of pounding before going down.
---Sideboard---Worked a lot in it, and finally looks well enough balanced, can counter every deck i can think of it would be a threat.
Well this was my first really competitive modern deck, i hope you like it and give me a lot of feed back, sorry for my bad english im 18 and from Argentina so we dont speak alot of english over here.
+1 if you liked it
