WHAT?!!!!!
You ended on that sentence?!?!
Now I'm on the edge of my chair till I find out more.
I'm with Mike - how can Superman's heart be so damaged when he has the healing aura, the yellow sun, blah blah blah?
(Of course, you could always plead Necessity of the Fic to the court.)
Hi, IO! Thanks for reading!
I do explain it a little bit later, when Clark and Bernie have a conversation. Basically, Clark sustained permanent damage while fighting Deathstroke (wasn't healing as he was almost having a heart attack due to Deathstroke's powers). Over time, that "bad spot" worsened/weakened his ability to heal in his heart.
Also, plot gods demanded it. (Sorry, Mike!)