Comet or DeathFire Torch
Which one would you prefer to stay?
Comet feels often unreliable and just meaningless at certain situations due to having a cooldown attached to it, making it so your poke is inconsistent.
DFT felt weak early-mid in raw power but was consistent and reliable as long you hit your spells, and you could always scale with it.
Forget about the Luden Splash procs because Luden should have never been reworked to a first item purchase. Also Scorch is one of the most useless runes along with Unflinching sadly.