Or C) Pochita is there(As his heart) so it doesn't really work.

I just feel like the War Devil's condition of turning something into a weapon doesn't just stop at "The more you're attached to something, the stronger the weapon" but also includes that "something's" name correctly. Like Denji convinced himself that the name "Denji" is his fake name and "Chainsaw Man" is his true self/personality.

Kinda similar to how Batman was able to say he IS Batman even when he had the lasso of truth wrapped around him as an example to what I mean.

Denji either: A) Convinced himself that Chainsaw Man is his real and true self and Denji is just his nickname or whatever because well... His goal seems to be not just helping Nayuta with her college tuition but also being the hero of he**, Chainsaw Man. B) The Public helped form the meaning of Chainsaw Man to the point where the name Denji doesn't count anymore.