i think Frostburn Weird is a tad bit out of place. id replace it with ether 2 Master of Cruelties and 1 Mizzium Mortars or 1 Master of Cruelties and 2 Mizzium Mortars

then move it to the sideboard and side it in against aggro

I love Master of Cruelties and I have had a lot of fun with Master of Cruelties and Ral Zarek together (the synergy is insane). Aggro is pretty heavy in my current meta so the Frostburn Weird is needed in main. I ran master as a 3 of and Ral as a 2 of in a previous build and I would not run one without the other. I would need to cut 5 cards from main for Master and Ral and I am not sure I can do that. What do you suggest cutting?

maybe 2 of ur milling jace and 2 opportunity. then if u want 1 weird. i think 2 ral and 2 master is a good number. u have the plans to draw u 2 cards but idk if it will work a well without the milling jace to back it up......maybe 2 or 3 Steam Augury ? i said 2 cuz that would open up a spot to a 3rd master but u would go down yet another draw card.....also cuz its CMC is 4 and the plans is 3...so 1 plans and 2 augury plus u have to discard the other pile and with the plans its just strait up draw 2. i would do 3 augury but its up to u.