This deck started out as just realizing that when you played with Keldon Warcaller and Phyrexian Scriptures, you could basically just boardwipe on the same turn, making it a 2 card Day of Judgement that left your creatures intact, if built correctly.
So, having such a synergy, I had to build around it. Give Voltaic Servant and Traxos, Scourge of Kroog were also very synergistic and aggressive given the above premise, I decided to throw them in. The rest of the deck sort of evolved over a few plays, and mentally, this is about as far as I can take it.
Angrath, the Flame-Chained was a natural inclusion for me. It gave me a later turn play, and a way to punish players who had low curves that played more cards after a wipe. It has a bit of a message mismatch, because I needed card draw, and I felt that your Sign in Blood effects were not good enough. So it conflicts a bit with the message from Howling Golem. I'm not sure what to replace it with.
Yahenni, Undying Partison was a suggestion from a family member, and it turned out to be a really good addition with the scriptures, so it's stuck. I also have a lot of legendaries at this point, so Jaya's Immolating Inferno just was a natural fit.
My sideboard is junk. I'm still trying to figure out what the meta even looks like.
Weakness of the deck that I know of : Green anything that runs with Thrashing Brontodon. This deck just folds to Artifact/Enchantment hate, and that is it.
Strenghts of the deck, that I know of : Gifts is very susceptable to this deck. Scriptures kills their grave just as they start their finishing setup, and it disrupts their main game plan.
Iffy Matchups - History of Benalia decks are a bit touchy. The deck can stabilize against them, but if you don't watch how you trigger your Sagas, or you aren't able to time a Jaya's properly, then you are in for a lot of a lot of hurt.
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In any case, I'm open to fresh Ideas. Please feed me some!