Fear isn't a deadly sin....
Lust isn't a sha...
Gluttony and sloth aren't sha....
The sha of pride has been pretty well foreshadowed for a long time now. I'm kind of surprised you're disappointed.
Not really derived from the notion of sins. They're just negative emotion.
Pride is the last simply because Pride is good...until it is bad.
Honestly, it feels more Star Wars "dark side of the Force" derived than any Judeo Christian "deadly sins" thematic to me.