Is twelve moon upper demon moon 1 in a whole completely different level than the rest of the upper demon moons?
Upper Moon 1 Kokushibo is definitely strong in his Moon Breath Techniques but can't seems to use any Blood Demon Techniques. I have to say, Upper Moon 2 Doma is quite near his level since his summons can already deal with Hashira level Demon Slayers. Doma's weakness is his glutonny and his overconfidence since he always lets his enemy injure him.