The Overveiw

Vadrock is such a powerhouse being able to get such a value train going. But not only just value but also an INFINATE COMBO. This combo can go off in manyways but it involves either goldspan dragon (since mutating onto it makes mana) or open the omenpaths (because you can repeatedly get it back with vadrock) these two options create a lot of mana and can get pretty nuts. 

Main card groups

We have the mutators 

      These are all the cards that can mutate on the Vadrock to keep getting us value such as the sea dasher octopus and Cubwarden. These are the cores of the deck, we do have to use some weaker mutators because brawl is a singleton format and their isn't many mutators in jeskai colors though.

The spells to regurgitate

      These are all the instant and sorcerys we return with vadrock for free, the most notable is See the Truth which feels made to be with Vadrock since it makes every mutate come with a draw 3. Open the Omenpaths is also one of those cards we are very happy to get again and again since it creates enough mana for us to mutate again.

The digging

       These are spells like Seize the Spoils and Thrilling Discovery that help fill the grave for vadrock and help us get to our combo peices such as Goldspan Dragon and Open the Omenpaths.

The side support

      These are things like Giant's Amulet which are sneakily powerful that don't seem good but in a mutate deck they can protect your mutate target so that your opponent doesn't just kill the thing you have been aspiring for for the entir match. mirror sheild does the same job but also might hose a fynn player one time. We aslo have Showdown of the Skalds Shark Typhoon and alrunds epiphany because skark typhoon creates an army when your constantly casting stuff from the grave and also makes a shark to start mutating off of and showdown can help set that up. But what's better then untapping with your combo commander once? well untapping with it 2 times of course because thats what alrunds epiphany does for us. Also a sneaky one that is in there is Whirlwind of Thought which can help draw us through our deck if we manage to mana combo. But it is also just a solid card. And oh yeah, Arcane Signet should be in every brawl deck.

The mana base

White is more of a splash, and we have double red in our commander so we want to make sure we get that (we like mutating more then not hopefully) even though there is overall more blue not being able to cast the commander sucks more. Command Tower should be in every multi-colored brawl deck.

Wrap up

So i do reccomend this deck and I have actually never played vs a Vadrock deck in the brawl que and i think he needs a lot more recognition. But as i play i will likely come back to the list and make small tweaks now and then so if you come back to shre the list with a freind and the list is slighlty different it is because I realized the deck needs something more (maybe a counterspell or two). But anyways if you read my long mologue I'd be very surprised but if you did that means you probably liked it wich means if you could please like the deck it makes me wan't to writ more things like this, but anyways take care and have fun.