Vanguard's multiplayer mode introduces a new game mode to the series, titled "Champion Hill", a successor to the mode "Gunfight", a 2v2 arena mode previously featured in Call of Duty: Modern Warfare and Call of Duty: Black Ops Cold War.
In the event store, you can get the Venom Strike blueprint for the M13B for 150 trophies. You can grind for these in regular MP, DMZ or Warzone, though since I am not a very good player I found MP to be the easiest. After getting the blueprint, go into DMZ and select the Venom Strike as your insured weapon.