This can be done in Custom Games or in a Public Match. I will be showing it in Custom Games
 
 
 
 
 
Head to Multiplayer then click the Custom Games option.
 
 
 
 
 
After that, select ‘Mode Editor’. Then click on ‘Arena:Slayer’ and then go to ‘343 Industries and select the ‘Arena:Attrition’ option.
 
 
 
 
 
Once again select ‘Mode Editor’ and in the ‘Options’ Tab select ‘Match’. Set the Round Limit to 1 and also the Rounds To Win to 1. Upon scrolling down in the ‘Spawning’ tab change the Respawn Delay to Instant.
 
 
 
 
 
Navigate yourself now to the ‘Health & Damage’ in the ‘Options Tab’ still and select Damage Resistance Ratio and change that to 0%.
 
 
 
Go to Team Damage Resistance and set it to one and the Team Damage Resistance Ratio to 10%. Then underneath the Max Shield Scaler should be set to 0% and further down the Max Health Scaler should be set to 10%.
 
 
 
 
 
Now go to the ‘Bots’ tab on the left and put at least 3 or 4 bots on your team and some on the enemy team. I recommend just having 4 bots on Eagle Team and also 4 bots on Cobra Team.
 
 
 
 
 
Finally for the ‘Options’ section hit ‘Attrition’ at the bottom and change the Team Respawn Count to 1 and select Revive Allies Action Time and set it to 1.
 
 
 
 
 
Finally you can back out and play the game. Just hit play. You can choose any map you want. Once you have loaded in just open fire upon your allies as they are now vulnerable to the player thanks to the settings we edited. Keep killing and reviving until the achievement pops.
 
 
 
 
 
A video guide:
 
 
 
 
 
 

 

 
 

 
 

 
 
This is all for Halo Infinite Medic Achievement Guide hope you enjoy the post. If you believe we forget or we should update the post please let us know via comment, we will try our best to fix how fast is possible! Have a great day!