Sevinne allows Jeskai to move into a more controlling build, grinding out games with value spells and the ability to double game-ending spells like Devil's PlayDevil's Play, Increasing ConfusionIncreasing Confusion, and (in some builds) Increasing DevotionIncreasing Devotion or Call the SkybreakerCall the Skybreaker
Prototype allows us to pick from two casting modes: do we want to pay an exorbitant amount of colorless mana for a big splashy robot, or a more reasonable amount of colored mana for a miniature, Hotwheels version of that same robot
While we already have cheaper draw engines off dying creatures like Morbid Opportunist and Grim Haruspex, these are all capped at one card per death trigger
For this ranking, I mainly focus on cards that have flashback themselves, and leave out most cards like Snapcaster Mage that give this static ability to instants and sorceries in your graveyard
Kelsien, the Plague Kelsien, the Plague is the only legendary creature with experience counters to come out of Commander 2020