This is a U/B deck that abuses the Cipher mechanic, backed up by control and destroy cards. This is also a budget deck, for those who like it cheaper, like me.
Counters and Doom Blade helped me to stay afloat while I play down around 4-6 lands. I also abuse ciphering Hidden Strings for untapping lands to use for counters, or for granting my creatures vigilance. Change Doom Blade to Go for the Throat against monoblack.
Sample scenario
Turn 1: Delver of Secrets
Turn 2: Say you got lucky. Transform Delver of Secrets. Play Hidden Strings, untap two lands. Cipher onto Delver. Cast Invisible Stalker (or two Delver of Secrets). Delver of Secrets attacks, untap two lands. You still have two untapped lands for counter.
So, after turn 2, you have a 3/2 flying and a 1/1 hexproof, unblockable PLUS two spare mana for counter.
Midgame you can use Hands of Binding to prevent creatures from attacking you, and level up Echo Mage.
I use Stolen Identity against players with big creatures, so that I can copy them. I switch to Undercity Plague against Control, or Mental Vapors against Super-Control Decks, so that I can cast it on turn 4. For Aggro, I use Vapor Snag or AEtherize. I can take out Bident of Thassa for four Mizzium Skin.
I used to start this deck with mill in mind, but in my opinion, I think Mill should be on a separate deck composition to be fully effective.
