You want to control the board by eliminating every card your opponent plays, and Dragon Fire allows you to get rid of a high-value target that would otherwise be difficult to Challenge down
It was a close call, but ultimately I chose Overview of Danitha, New Benalias Light Danitha, New Benalias Lights ability lets us cast one Equipment or Aura from the graveyard on each of our turns, thereby looping in two other synergies: graveyard and Auras
Prismatic Evolutions The Eeveelution SIRs from Prismatic Evolutions are some of the most visually stunning cards ever printed, and sealed product demand has not cooled since release
If you do, it enters the battlefield as a copy of one of those cards with a number of additional +1/+1 counters on it equal to the power of the other card. Basically, they can become any creature in any graveyard, and then get some +1/+1 counters on them to boot
If you were looking to play endurance or grinder control and you fail to find any suitable life gain then you likely have to try and do something else