I thought of this as an idea for the stadium mode . The mode is based around The Reckoning from the Junkerqueen short. I see two variations of this.
For stadium this would operate as a last team standing with the objective of the game being to kill the other team. This would likely be a shorter mode so I believe this would fit well in stadium. It could possibly include the resurrect teammate function from the PvE missions. Additionally a wave respawn for dead allies with limited number of respawns would allow for the game to last slightly longer and result is wacky team compositions as members of both teams run out of lives.
If not the above I believe this would be a fun limited time mode or a fun variation on the arcade deathmatch.
I hope this doesn’t get buried. Please respond with your own suggestions for balance or fun.