Fill your deck with instants/sorceries that can be cast from your graveyard such as flashback (Ignite the Future), jump-start (Chemister's Insight), and aftermath (Refuse // Cooperate) to maximize Sevinne's ability
As I mentioned a moment ago, the only downside is that we mostly played midrange and control (Dimir Control twice, plus Golgari Midrange, Jeskai Superfriends, and Esper Stax), so we didn't really get a chance to see how well the deck would perform against aggro, although Happily Ever After has a pretty insane ability to grind through disruption and eventually win the game with Happily Ever After
Yes, you have some good acceleration and card filtering via gems like Dockside Extortionist and Faithless Looting, but there arent many other red cards like these
They may contain any of the following: 1 Battle card 1 full-art basic land 1 nonfoil or traditional foil Multiverse Legend 1 Rare or Mythic Rare card from the main set Battle cards, Multiverse Legends, and one Rare or Mythic Rare card can always be found in a Draft Booster