The manga has already heavily supported the opinion that Merlin, Escanor and Ludoshel will win in the battle against Cusack, Chandler and Zeldoris. Let me explain.
We know that the battle takes place before Mael's awakening. (Chapter 285, Page 10)
Mael's awakening causes everyone involved with Mael to suffer massive headaches as Gowther's spell collapsed. This caused them to be unable to fight properly. However, King was not affected at all because he did not exist when Mael was still an archangel. (Chapter 273, Pages 8 and 9).
Here comes the biggest hint to Merlin's victory, we see that the battle has stopped as Ludoshel, Cusack, Zeldoris and Chandler (Implied) have all been incapacitated because Mael awakened. (Chapter 273, Page 15).
However, Escanor and Merlin are unaffected and can easily achieve their objective now with the demon side incapacitated. This is because Merlin anticipated this and took advantage of the mind collapse as Gowther told her the truth of Mael beforehand. Merlin probably put up a counterspell to make herself immune, Escanor is the same as King. (Chapter 253, Pages 4 and 5)
Merlin has enough speed to achieve her objective because she has tricked Chandler and Cusack already. A small opening is all she needs for a victory. (Chapter 286, Pages 10, 11 and 12)
Not only do they have numerical superiority, but they also have Merlin's intelligence. Hence why Merlin declares the battle is not of numbers but of intelligence and the main objective to free Melodias. (Chapter 286, Page 12).
We know that the battle takes place before Mael's awakening. (Chapter 285, Page 10)
Mael's awakening causes everyone involved with Mael to suffer massive headaches as Gowther's spell collapsed. This caused them to be unable to fight properly. However, King was not affected at all because he did not exist when Mael was still an archangel. (Chapter 273, Pages 8 and 9).
Here comes the biggest hint to Merlin's victory, we see that the battle has stopped as Ludoshel, Cusack, Zeldoris and Chandler (Implied) have all been incapacitated because Mael awakened. (Chapter 273, Page 15).
However, Escanor and Merlin are unaffected and can easily achieve their objective now with the demon side incapacitated. This is because Merlin anticipated this and took advantage of the mind collapse as Gowther told her the truth of Mael beforehand. Merlin probably put up a counterspell to make herself immune, Escanor is the same as King. (Chapter 253, Pages 4 and 5)
Merlin has enough speed to achieve her objective because she has tricked Chandler and Cusack already. A small opening is all she needs for a victory. (Chapter 286, Pages 10, 11 and 12)
Not only do they have numerical superiority, but they also have Merlin's intelligence. Hence why Merlin declares the battle is not of numbers but of intelligence and the main objective to free Melodias. (Chapter 286, Page 12).