Version 1.
one merc ability. medics can make a “clone capsule” that will be a spawnhost for their teammate for 1 life, just like in ETQW strogg spawnhost in the dead bodies.
very big cooldown (1-1.5 minutes)
when that capsule is made. any team-mate can press “use” on it, i.e. give their DNA samples, so that in next spawnwave they will spawn in the clone capsule.
version 2.
only difference is that this is a more complicated 2 merc ability
medic+engereer
-medic drops a simple 1-person capsule (medical facility)
-engineer “builds” his part - capsule enlarges up to 3 persons