As said in First Founding, p.110, under the Greater Follower option : Space Marine Implants

I looked for it, players looked for it, its driving us to heresy (Core rule book: nope). Does it even have a description/rule somewhere? Have anyone seen it/used it ?

All help appreciated.

I think they would mean Mechanicus implants. Which makes much more sense than stuffing sacred geneseed in some rando.

Rules for space marine implants are found on page 36 of the main rulebook. I am fairly certain the trait was included intentionally.

Many chapter serfs are aspirants who, for one reason or another, failed to successfully become space marines. While it is not impossible a serf may have gotten to the implantation stage and the geneseed fail to take, or was incompatible with the aspirant's body, the implantation rites of some chapters would preclude this. Blood Angels implant all the organs at once and lock you away in a sarcophagus for a year, failure to take could happen but its more likely you're body's imbalance would kill you. Space Wolves impart you with the Canis Helix then leave you out in the frozen reaches of their planet, incompatability here either get's you killed (being naked) or turns you into a slavering were-wolf like monster.

It also allows a space marine follower, such as a neophyte. (average skill for a greater follower over 9 characteristics is 33). For instance you can easily make a space marine greater follower with the rules, using almost every starting space marine skill and every starting talent/trait (trading extra traits for skills). The only exception a GM would have to give would be the starting equipment, if you wanted to give the follower astartes armor. The space marine implants allow the follower to do all the things a space marine can (hibernate, spit acid, etc.).

It seems very odd to me that a Chapter would just send one of its Scouts or other Marines with the PC as a follower, outside the normal Chapter chain of command. Or even a failed-but-implanted aspirant. Usually when an aspirant is implanted and still fails, it's because they die - either in training or because their body rejects the geneseed organs and they go into shock and die.

If that follower is a Space Marine why isn't he independently taking the Apocryphon Oath? From the fluff in FF/HtC it sounds like a lot of times that will just happen even without official Chapter permission, following the Marine being present at some horrible event in the Reach and swearing to stay for vengeance or honor. I don't think that the DW would let non-sworn (or not in-training-to-be-sworn) Marines just hang out on its secret space stations.

So I'd be fine with a serf, but your Space Marine having a follower who is also a Space Marine, even for Black Templars who have that kind of mentorship tradition? I'd say no.

It also allows a space marine follower, such as a neophyte.

Sounds useful for a Black Templars character, imo.

Thank you all for those awnsers.

I won't lie, it is indeed for a young oh so unlucky neophyte follower minion. We decided to give him the trait but not access to all implants (only phase 1 to 5). I was hoping that the follower trait would have an entry description somewhere but oh well will do with some tweaking.