I'm just saying, Natsu has perfectly analyzed Fighter's Movements, to the positions of their attacks, the form of their defenses, and even their Breathing Patterns, his enhanced Senses especially in Dragon force, let him do much better against opponents and read there movements, also Natsu has eaten tons of different Magic and absorbed them, Flame of Rebuke, Lightning, and even Etherion, which is pure magic itself, Zancrow's flames are a higher form of Natsu's Magic, so he needed a trick to eat them, but he still succeeded, he could eat hellblaze and get a boost in power, and since this is unarmed Meliodas, he's not using Revenge Counter, Also since he's not allowed to use Wrath or his Demon Mark in this fight, No regen, And yes, Full counter makes Ranged attacks useless, however Natsu's Close quarter combat and magic, still apply here. This is a heavily weakened Meliodas, in fact it's the beginning of the Series Meliodas, which is his weakest form
I don't think this form of Meliodas has enough to put Natsu Down, Full Counter won't work, while Natsu has to just keep wearing meliodas down, and can even consume Hellblaze if he wanted too, Natsu takes this mid-diff