Can a Pyromancer Sorcerer deal fire damage to a creature that is under the effect of Invulnerability?
The spell Invulnerability (XGtE) states:
You are immune to all damage until the spell ends.
The class feature Fiery Soul (Plane Shift – Kaladesh) states:
At 18th level, you gain immunity to fire damage. In addition, any spell or effect you create ignores resistance to fire damage and treats immunity to fire damage as resistance to fire damage.
My gut reaction is no, because Invulnerability states you are immune to "all damage", not "fire damage" or "all damage types".