Where can i get a legendary FIRE sword?

[prime11]

i got void and arc, the 2 from the current season, but really want a fire sword, just incase i need that element. I like to carry 1 each with me
i have a blue one, but rather have purple.

-I'm just lookiing for easy method, prefer pve. not into pvp

[Bluemenkranz]

Leviathan's sword, the It Stared Back or the Prophecy dungeons Negative Space

[Raeden]

When you say fire , do you mean solar?
If yes
Then you can try and get either just in case from gambit reckoning or future safe 10 from lost prophecy boxes from brother vance
But im not sure if those swords are good so probably try and get the menagerie sword the deaths razor