This is probably gonna sound like a dumb question (and I’m sorry in advance) but I literally know the bare minimum about the Flashfam and their lore, so here we go. You’ve talked before about Kon being Bart’s “Lightning Rod” and from my understanding, it’s more or less a soulmate. Can you tell me more about that?
Hello and apologies for taking so long to get on this one.
A "lightning rod" when it comes to Flash Lore is basically someone who prevents a Speedster from becoming one with the speedforce, or acts as an anchor to find their way back when otherwise lost in speed related... debacles. Like a bolt of lightning to a metal pole they are attracted to them. They are people of whom a speedster has an emotional bond with, romantically, platonically or even antagonistically.
The comics naturally focus more on those that share a romantic bond with a speedster, but there is evidence to support that any strong bond can make a lightning rod regardless of the type of bond they have.
Jay's lightning rod is his sweet Joan of whom being his lightning rod had her own aging 'slowed' to match his (it's a little more complicated than that but for simplicity that is what is going on).
For Barry, Iris is his lightning rod which he was able to use on several occasions to pull himself out of the time stream and back to his own time.
Wally's legendary bond with Linda as a lightning rod is blatant as she helped pull him from the speedforce after he had already merged with it.
There are other instances of Iris and Linda both being lightning rods where not only do they help their speedsters manage their own powers, but by being lightning rods it helps the speedster keep them safe and prevent their own deaths or grievous harm, or in Jay's case extend Joan's life.
The tell-tale sign of a lightning rod for a speedster is of course a romantic bond, or a persistent attraction bringing the two together.
The comics will also blatantly tell you who a lightning rod is eventually using those words, where by then they get... bonus features (like Joan having her aging impacted, Linda getting powers etc).
For Bart we don't have the comics using those specific words for anyone, but in looking at the behaviors of other lightning rods and their speedsters we can sort of extrapolate that Kon, Cassie and Tim are his lightning rods with possibly Cissie (realistically she would be one but she dropped off from continuity so we didn't get to see her much after 2003).
Kon being one with an intense 'pull' for Bart is something that has the most evidence in Young Justice 2019 when Bart worked exhaustively to find Kon and to bring Young Justice back together.
When the newly formed Young Justice sans Kon were all zapped to Gemworld they were all scattered but it was Bart who appeared literally right next to Kon. Everyone else had been deposited in more random places, but not Bart. This suggests that while he does have a bond with Tim and Cassie, it is to Kon that he may have a special bond with.
There are other instances of Kon's existence being a focal point for Bart throughout their comic relationship such as during the World Without Young Justice arc where a de-powered mundane Kon was able to give Bart the courage and strength to overcome his deep paralyzing fear to reabsorb his dying scouts.
Also Kon and Bart have an intense friendship where there are multiple instances where they pick each other up and seek each other out which is at least the grounding basics for a lightning rod. For further reading on that you can look at the Konbart Manifesto.
To quantify if a lightning rod is a soulmate is a little mushy. If you are a romantic sort and the idea of soulmates pleases you tremendously then yes a lightning rod can be used to describe one, but there are more 'extras' that come with a lightning rod than just an intense burning love and a 'meant to be' attraction.
There is something more physical, metaphysical, spiritual and atomic about their bond than it being a divine uncontrollable force. There is an element of spookiness involved for sure, but there also is an element of choice about who become one based on built up love.
A lightning rod is something as profound as a gravitational pull for a speedster; their relationship is like Earth and our moon where Earth is a speedster and the moon is a lightning rod. Without the moon as a ballest Earth's stability in orbit would likely change catastrophically and for a speedster this is also the case.
I hope this makes some semblance of sense.
TLDR: A lightning rod is like a soulmate that a speedster has semi-control over but is no less spooky and endearing.