Amayon projects a massive upward portal that requires a large number of souls and will pull surrounding entities into Sheol.
Samantha identifies the prince's continuous sky fire as a portal spell rather than an attack. Ordinary evicted demons open small ground portals after securing required souls, but a full prince needs a much larger door and substantially more payment.
The red cloud forms hundreds or perhaps a thousand feet above Havana and grows while Amayon pours fire upward. Once active, it should pull nearby entities skyward like a powerful vacuum.
Ines is not making Amayon cast it; she is trying to hold him while he resists and continues. A red sunset-like effect is already visible from the Bahamas, suggesting the portal's influence is not strictly local.
A growing red vortex high above Havana drawing fire and air upward from a vertical demon-snake.
The portal is Amayon's attempted return home and the possible engine for Carl's global rescue plan.