Yeah but he's way bigger than he was before
The size change is very inconsistent but the fact that they get bigger is consistent

Pontiff is also a human iirc and he's pretty big for a human, and the profane flame he uses also has its roots in the Dark Soul so maybe it really is just that the Dark Soul specifically makes you big

The Abyss does grow, after all, and densely packed darkness created The Deep

So you know how those huge rats can sometimes drop a humanity?
That's because they ate a bunch of humans
The Dark Soul makes you big
But there are also non-human big characters so maybe it's just souls in general

I always assumed Smough was so big because of his cannibalism (like the huge rats)
Then when Ornstein sucked up his soul he got all the big that comes with it

Will your crimes ever be forgiven?

i do this but actually follow through because im superstitious

Winter melon in the back

Rats are highly intelligent creatures
Except this one