Hey there. You do not need the oldest weapons, but the newest ones may not have been added to the pool of allowed weapons. For ones that are guaranteed, you could use any of the old Gambit ones or Gambit Prime ones, so if you have a Night Watch, Gnawing Hunger, Lonesome, Bad Omens, etc, those would work. Malfeasance is fine too. I am not sure if the reprised Trust he now offers, counts, I'd suggest avoiding it. For newer weapons, anything up to Season of the Risen, I have seen confirmation that they work. So Bottom Dollar, Crowd Pleaser, Trinary System, Borrowed Time, Servant Leader. Last season, I also had confirmation that Dead Weight, Yesteryear, and Albruna-D, did NOT work, so maybe avoid those. Maybe they've been included, maybe not. Is there a new weapon this season? It almost certainly won't work. One last note - old Gambit pinnacle/ritual weapons do not work. So Hush, Breakneck, Python, Delirium, etc.