Hive, because they are literally fear.
(Note that this is all theory)
The Fallen are pride, the Cabal are rage/destruction, and the vex... well... I'm not actually sure.
English
-
Arrogance, so pride.
-
The Fallen? No. They're trying to rebuild to some lost grandeur, with the Great Houses and royalty-like organisational structure.
-
Fallen are greed.
-
Intelligence