Tips to Beat the Mission to Join the Guild
If you have a sniper rifle you can try to snipe the enemies as they arrives in the pods in their heads.
A headshot with a sniper rifle instantly kills them. You have to be fast.
They stay put when the pod lifts for like a second and that is your opportunity to headshot them.
Once you miss and the fight begins you need to use cover and you need to watch your back.
They will try to clobber you from behind. You need to focus on trying to hit their head as that does big damage and staggers them.
If you start to get overwhelmed you can as a last resort move away from the console and they lose interest in you and rush to the console to try to interrupt it.
You can just kill them once they reach the console as they stop fighting and just stand there. Make sure you kill them before the interrupt sequence finishes.
Regarding healing I’m pretty sure that happens naturally if you go long enough without being hit.
Note: healing comes from healing abilities unlocked when leveling up the soldier class.