After the fall of the covenant the elites who didn’t want to join the banished needed solitude and went to the enemy for help saying they wanted help. They were then expected into the unsc. The engineers who made the spartan armor are still getting use to the new armor but it’s going well. The elites are getting use to the weapons that killed there kind but they show promise and have remarkable aim (even though you can aim the MA40 in halo) the UNSC marines didn’t like working with the elites until they found out that the elites are willing to die for their team so they excepted them and now the elites help with the fight against the banished