The deck has lots of backups like Grapeshot (if Tendrils is gone or you need removal), Thermo Alchemist (lower cmc than Rockslide Sorcerer), Sorcerer Class (I've never actually cast it, but it's there in case of an emergency) and the Birgi/Grinning Ignus Combo (With Birgi on the field and 3 mana open, cast Grinning Ignus, making 1 red mana off Birgi. Use that mana to bounce Grinning Ignus and make 3 mana. Use that 3 mana to cast Ignus. Rinse and repeat for infinite storm count).
Displacer Kitten can combo with Kess if you have enough instants and sorceries in your grave.
It also has a few (strong) pet cards like Sunbird's Invocation (every cast from your hand digs and casts a free card before resolving), which has won me so many games with so many different decks (basically my favorite red card alongside Mizzix's Mastery).