You don't need to go that crazy for activating At Any Cost
ASAP. You can just put 4 copies in an already solid mono S list and go with it. We have a solid midrange plan with wonderful units and supreme removal, then we add just a bit of combo finish as dressing for memorable and fun games.
I'm very happy with running a bit of hand disruption in form of Shakedown
. They can be used to get rid of anything that can cause trouble including units, removal and attachments.
Cull the Deck
and the nightfall effects let you turn through the deck and find what you want more quickly than you might initially expect.
Of course you can splash a secondary color to cover up shadow's weaknesses, but I'm very happy with this list as is.
I'm running a lot of very good cards as 3-offs here; I recently started running even very powerful cards as a 3-offs and only run a few cards as 4-offs, those being the centerpieces or something I can almost always happily play. I recommend you to do the same with very good cards that are situational or cost more than 4 power (run only 3 copies instead of 4). more diverse games, more options and less shiftstone to spend.