Orpheus Fool's name is up this week, what do you want for the challenge orpheus?
I would go with : Origin, Assault, Classic --> HIghest score
Also Pilgrim if you are taking suggestions I was thinking Origin zones or assault HW. Or maybe Conduit Lonewolf blitz zones.
OR! Junction trooper CTF FWTF ON!
I might be a little late.
Good kill an enemy tank only using an assault rifle. It is possible just hard BTW.
That's a hard challenge to track effectively. You can do a whole lot of damage to a tank with any weapon and then just pop it with a rifle a couple times and it registers as a rifle kill.