I joined random lobbies on Apocalypse and so far I have beaten Ravager by really fighting him, Labyrinth Sentinel, Sha'Hala, Nightweaver and Annihilation but Reggie doesn't carry the ring.
Do you need to beat a full campaign run to get the ring?
#Conditions to unlock Devoured Loop
distant cargo
errant terrace
The issue with doing it in co-op lobbies is that it’s very easy for any sort of connection issue to mess up your game claiming the boss kill credit.
You should technically meet the reqs for Reggie to sell the ring, but you may have had a DC or something small that messed with your boss kill credits. Try going through and just testing in Apoc Adv to see if it was one of the rerollable world bosses, if not, you missed a kill credit for Lab Cube and or Anni.
We usually try to recommend doing the Apoc runs in your own campaign, because at that point you have no way of missing the kill credit because it was your boss and you weren’t there via what could have been an unstable connection.