Kohron, The Prince of Strife did not doubt that Rowan before him was a true Demon, not just because of his actions, but because every inch of Rowan's body was filled with an Abyssal Aura that was instantly recognizable to those who knew what to look for.
The Tower of Greed was an Abyssal Origin Treasure, far more powerful than a standard Origin Treasure which was already extremely powerful in its own right, and few gods were able to forge an Origin Treasure in their long lifetime.
With every usage of this powerful treasure by Rowan, the Aura of the Tower of Greed would settle like a shroud on the user, it was one of the many processes to bond with an Origin Treasure.
Yet there was a disturbing hitch in this process whenever Rowan was using this treasure.