Mulligans
General Mulligans
In general you want some combination of these cards in your opening hand. I've organized the mulligans by what they're the best/ideal against, but you probably want to keep any of the 3 mulligan sets if you get 2 or more cards.
All of them are good and will usually help you get off to a quick aggressive start that this deck needs
Aggro Mulligans
You just want to get on board as early as possible. Upgradeable framebot lets you trade with the small minions, but also isn't threatening enough for your opponent to smack on turn 2, so you'll usually get off a 3 mana 5/5
Midrange Mulligans
Your standard best start. 2 mana 4/5 into 3 mana 5/6 into librarian or maybe just cleric -> anything -> 3 mana 5/6 -> unsleeping soul. You'll consistently get to a point where you have like 16/20 worth of stats before turn 5, then a Leeroy can actually just be enough to kill your opponent before they even get going
Control Mulligans
There are control classes you can burst down, like mage, quest paladin, but mostly against warrior you'll need these.
The biggest problem with this deck is that you run out of gas, so if you're playing against one of the control classes that you can't burst down, you just want your card draw engine, so you can plan your damage effectively and maybe go for the divine spirit inner fire combo to end
The goal with this deck is to get on board as early as possible and exert pressure. Force your opponents to play at your speed or kill them if they don’t. You want to get some Ancient Watchers and Arcane Watchers going as quick as you can, so they have to answer something. Don’t be afraid to make trades against other aggro decks because your minions are just bigger. And face is the place vs control/slower decks. If you don’t have Leeroy Jenkins , swap him out for SN1P-SN4P. Both can have a place in this deck, SN1P-SN4P helps you regain control of the board and Leeroy hits face, different playstyles will influence your mulligans.
If you want to play slower, swap out the Spellbreakers and Upgradeable Framebots for Mortuary Machines Conjured Mirages and maybe even Soldier of Fortunes, but this one is more for tempo/aggressive play and can be subbed into this deck as is.
I just noticed myself running low on silences in some games, or not drawing the 6 cards in the deck with the effect, so adding 2 more definitely helps.