Burn is now possible in limited!
Heartfire Immolator is no Monastery Swiftspear, of course, but it has Prowess and an extra ability that can finish off a creature or a planeswalker.
This will also work great in Izzet Spells deck alongside Spellgorger Weird and a bevy of removal spells. But in general, Heartfire Immolator is a solid 2-drop, which would find a home in any red deck.
If you see it in your first pack, don't hesitate to pick it up — unless there is a bomb rare right next to it.