First-Person POV, Tobias "Four" Eaton
The whole gimmick of Four: A Divergent Collection is to see things from Four's point of view. There are even three scenes from Divergent included at the end of the book, but told from Four's eyes. (That's Four's eyes, not four-eyes; we're not insulting anyone who wears glasses).
Veronica Roth even explicitly draws our attention to this point. When Four realizes how similar his initiation was to Tris's—they both come from Abnegation, they both have no friends, they both change their name—he ponders,
How is it possible to live the same story twice, from different vantage points? (4.133)
This is a very meta observation from Four, who is watching Tris walk in his footsteps.