I'm glad you're still doing these mono-decks. The league has been taking up a lot of my time. Plus I'm playing more FGs to upgrade my different PvP decks.
That first deck is definitely a good Death themed deck. And the dual deck looks good too. I don't have time to test it, but what if you got rid of a Dragon, Bonewall, and maybe 4 pillars and took 4 Ash Eaters and another Deflag & Rain of Fire? The Ash Eaters will help you get fire quanta faster for your RoF while also being fodder for your Bonewalls and Boneyards if your opponent takes them out.