WIP section, I'm just putting some notes here.

W/R Prison. A neat little prison deck I made. Removal and board wipes for the early game, win conditions of Outlaws' Merriment and big Chandra supported by medium Chandra for card advantage and Felidar Retreat. Karn toolbox with 15 different artifacts to choose from, and an auto-include companion because we meet its requisite by accident.

It maindecks a lot of cards that should be sideboard cards. But see, turn one Grafdigger's Cage sees more turn one concedes than you think. Mostly from Collected Company Decks, Uro, and Lurrus decks. Sorcerous Spyglass is also very good in the maindeck; pretty much every deck has some variety of activated abilities. Of the best decks in the historic meta, it is a maindeck answer to all planeswalkers (i.e. Big Teferi, Ugin, Nissa, Big Chandra, Narset, ect.) and also has a lot of side cases such as Jund sacrifice. 

And if we don't need them? Fire Prophecy can loot them. Beautiful, right? 

Karn is a very powerful card to put in a prison deck. In an uncertain stalemate, it gets us what we need. More taxes, lifegain, card draw, and even limited forms of removal. Plus, it's the best answer to our worst matchup: artifact ramp.

MATCHUPS

Best matchups: pretty much every creature-based deck. All the mono decks, red, green, black, blue, and tribal elves and goblins are obliterated by this deck. Lurus decks are hit pretty hard too. Maindeck Anger, Chandra, and Grafdigger's.

A hilarious interaction against monoblack: Justice Strike on Phyrexian Obliterator. Kills it and THEY have to sac the permenants. FIVE. Permenants. 

Decent matchups: control decks. We have a lot of tech against control decks that to win with PW's or Uro. But sometimes we get stuck with all the board wipes and removal we just don't need. Neoform combo is turned off by Grafdigger's Cage so that's neat.

Worst matchup: there is one deck we lose to nearly every time: artifact ramp. Ugin hurts. A turn 5 or 6 Ugin hurts worse. There are few answers to to Ulamog. There's no way to stop Ulamog for this deck, and we're not fast enough to win before its out. Maybe we draw Karn and shut off their ramp. Maybe. Maybe it's just me, because there is maindeck artifact removal (Abrade) for Forsaken Monument and others, and there is Ixalan's Bind for Ulamog.

POSSIBLE MODIFICATIONS

I might take out the Chandra, FA's for more Karn's

Anyways, I got to Diamond from Bronze with it, will try to make it Mythic, let's see what happens. I'm personally short on wildcards, so the sideboard may be a little wonky. This probably isn't the ideal deck, but it's what I've used so far.