Overall account level / rank + combat record (stats)

Overall account level or rank so even after you level up the factions and weapons, you still have something to grind for.
A system like CoD with leveling or Halo reach with their ranks (leveling)
This shouldn’t be something you can easily max out. Halo typically did a great job. Some ranks you never even saw because of how much time it took to obtain them.
Gives players something to play towards.

And combat record to display overall stats. (Kills, deaths, objectives, assists, portal kills, etc)
Leaderboard would be a nice addition on top of the combat record as well.