I do not consider that canon.
You will not convince me otherwise.
Instead, I' am here to tell you what I consider his 'true' Madness to be.
Since we will never really know what his canon Madness was (again, THAT stupidity was NOT his canon Madness; don't tell me it was) I can only consider my guess to be my headcanon and that is how it will stay. You all can choose if you believe it or not.
I' am here to tell you what I'll be believing in regards to the Kishin Crona, from here on out.
I believe his Madness to be the "Madness of Bonds" (Or "Ties")
He had a fear of getting close to other people thanks to his original relationship to Medusa, and it was his friendship with Maka that was his first taste at what a true bond/tie to another person felt like.
So when Crona killed Medusa, this is why he went on to try to cut himself off from everyone else. He wanted to cut his bonds to everyone, including Maka.
THAT IS WHY HE GREW THORNS; TO KEEP EVERYONE AWAY
And it was in his crazed state, he believed that by having bonds to anyone, you were being held back from your true self. The very reason hewanted to become a Kishin was to break the world's bonds, so that everyone could experience true freedom!
This leads to Crona being defeated through the power of bonds.
(And then eaten by Asura)
It is inside of Asura, that Crona realizes that he still has a bond to Maka. It is a bond so strong that he is willing to hold on to the last bit of life he has when it would be so much easier to just let the Madness overtake him and erase his existence.
All the trouble he went through to cut his bonds to people ended up just revealing how strong a person's bond can be, and how its not so simple as just cutting a bond and it being that. One would still emotionally be connected to them even if not being with them.
In the end, it is through his bond with Maka that the Kishin is defeated and Crona reaches godhood.
(And that's not even counting how Asura, before being sealed away, warned Crona about trying to depend on those bonds he has to Maka and the others. He warned him that it wouldn't last forever and eventually Crona would be overtaken by the Madness one day...)
So with all this, what does it prove?
MADNESS OF BONDS IS WHAT IS TRULY HIS MADNESS
(AND WHAT MAY, ONE DAY, BE HIS DOWNFALL AS ASURA PREDICTED)
BONDS; BECAUSE THAT IS WHAT CRONA'S WHOLE STORY WAS FOCUSED AROUND