While winning five coin flips sounds absurd, in reality it's incredibly hard to pull off, even with Krark's Thumb (it's only a 25% chance with a Thumb out)
Sevinne, the Chronoclasm's copy trigger happens whenever you cast your first instant/sorcery spell each turn, not just on your turn
On the Ruby side of things, you can expect the usual suspects
You're not just running Zodiark for the board impact - you're running it as a value engine in Mazirek, Kraul Death Priest, Yahenni, Undying Partisan, or Mikaeus, the Unhallowed builds
So at first glance, its not that easy to determine the exact value
Jor Kadeen, First Goldwarden Jor Kadeen, First Goldwarden perfectly fits into the deck theme of equipping creatures and swinging hard