Mechanized Investigation is all about Mechanized Production and cards that create Clues.
The creatures Tireless Tracker, Erdwal Illuminator, Thraben Inspector, and Bygone Bishop all produce clues when something enters, land, and double investigation. Tireless Tracker pumps up with Clue sacrificing, Bygone Bishop triggers clues for playing any of the creatures as all of them are under 3 CMC. Selfless Spirit helps protect your creatures especially when using Fumigate. Torrential Gearhulk helps with a flash-in creature and can help recast some of the instant cards in your graveyard like
Confront the Unknown
for pumps and more clues or protection with Heroic Intervention.
The enchantments in the deck help create clues with something entering or dying.
Weirding Wood
helps with 2 mana of a color or using it to create 2 mana you don't have. Mechanized Production is used as one way of the alternate win condition using the clues.
Now Open the Armory is used to fetch either your Mechanized Production or
Weirding Wood
as they are also Auras which is what Open the Armory does.
Now for protection of your permanents, Heroic Intervention and
Selfless Spirt
help with that. Heroic Intervention protects all your permanents with Hexproof and Indestructible so your clues, creatures, and enchantments do not get destroyed. Selfless Spirit helps protect your creatures from being destroyed so you can block and still win thru damage.
There's only one pump spell in the main deck which is
Confront the Unknown
. It uses all the clues you have created to pump up a creature with +1/+1 per clue you have. It can help pump to block or use it with your fliers to hit for some easy damage.
Fumigate can be used for several different things. A board wipe is pretty obvious as it destroys all creatures. Combo that with Selfless Spirit and you protect your board while wiping your opponents. Second feature is the life gained with it by destroying their creatures. Sylvan Scrying is to search for the lands you need including dual lands.
The last card to help your deck is Sigarda's Aid. It helps you flash in for the win or to help put out
Weirding Wood
onto the battlefield for extra mana and a clue.
The Side Board is just to either slow down your opponent with tapped creatures ETB and gaining life with Authority of the Consuls. Exile your creatures (only to help your win condition) or theirs with
Declaration in Stone
. Make creatures less of a threat with
Jace's Scrutiny
and create a clue. Tap a creature with Press for Answers and create a clue. Counter spells with Disappearing Act and and bounce back a tapped land and possibly replay it helping Tireless Tracker or saving it for a pump spell or something else. Destroy artifacts and enchantments with
Root Out
and create a clue. And last is a counter spell with
Confirm Suspicions
while creating 3 more clues.
And that is Mechanized Investigation.