Mulligans
General Mulligans
Keleseth is the obvious one. Fire Flies are always good to play turn 1. Tar Creeper should be kept vs aggro, especially if you have The Coin. Frost Lich Jaina should be kept in some control matchups, namely vs Control Mage when it often comes down to being able to play your Jaina first. Glacial Shard is also a very good one drop against aggressive decks and/or decks that struggle to deal 1 damage.
I hit legend pretty quickly with this deck (a total of about 8 hours from rank 5). Unfortunately I don’t have a tracker to know the exact winrate, but I’d say close to 60%. Because of the high amount of value-generating cards it packs a punch that control decks are usually not able to handle. Also cards like Gluttonous Ooze, MCT, Tar Creeper and Saronite Chain Gang make the matchup against overly aggressive decks a lot better. Spellbreakers are still very useful even after the decline of Contol and Cube Lock. Baron Geddon is the best catch-up card, especially with Jaina, when it also serves as a very good heal. Overall a very fun deck to play.