I can't see this happening. Makes no sense for Enma to start absorbing elements, wasn't mentioned during it's introduction.
That Drawing is not just Fire, it's a Yokai/Spirit (That's why it can pass though walls)
So Enma might absorb that Spirit & gains Fire Ability as Side-Effect
Usopp clearly said Zoro can summon Fire
It's 100% certain that Zoro will gain a Fire Sword & there is no better chance than now