On the issue of corruptability I would think that they would be rather watchful of taint and likely "cleanse" any brothers suspected of this with flamers. the reason I brought this up is because one of my group wanted to go ahead and create a backup character that was a black Templar techmarine that purged his entire squad prior to joining the deathwatch. I would like to hear your thoughts on this.

It sounds a bit radical, but ... why not? The only things I'd add would be a thorough investigation following this incident (was he right in doing this?), and clarify what exactly led to such a drastic escalation (perhaps a prolonged mission where the squad was cut off from their battle-brothers for some time?).

The good thing is that this background adds a lot of potential for roleplaying. Was this Marine sent to Deathwatch as some sort of penance, reward, or simple pragmatism, as he is now without a squad? Did he volunteer because he blames himself for not noticing sooner and possibly preventing his brothers from falling (regardless of whether they actually fell)? Does he carry survivor's guilt as the only remnant of his squad? Does he miss and think of his battle-brothers?

And ... does the rest of the Kill-team know who they are dealing with here?

that was really helpful thanks also considering that this person acts like a ditz sometimes (as an ultramarine apothecary he forgot to collect fallen brothers geneseed and the dark angel tactical threw a codex at him) he not noticing would be true to his character lol.

The question would be why that kind of super hardline guy would be chosen to go to the Deathwatch. Chapter leadership knows that you need a flexible Marine to be seconded who can handle the culture shock.

I keep forgetting Kill Teams have different types of Astartes within their squad. From my personal opinion, when I run Deathwatch games I tend to keep a squad or kill team the same type of Astartes. This gives me the chance to feel more like group then different chapters. I would personally keep the Black Templar within the Templar squad and like Lynata said, investigate why his squad was purged. Templars are for the very reason fanatical and zealots. It wouldn't be so much radical, that something their squad did must have been un orthodox or against the codex for him to have carried out the termination of his battle brother.

Maybe his squad pillaged and razed cities and whole planets. This dominating effect over lesser people could give the impression of anarchy and oppression. Maybe he found out these people believed in something other than the Emperor and the peoples lack of participating in switching to the Imperium rendered them enemies of the state. The people of this planet could have believed in wytches and the warp which wouldn't exclusively make them heretic but in the eyes of the Templars, maybe your former squad took it too far.

Interesting point I see where you're coming from which then brings up a whole host of other questions, such as how far would the Black Templars have to go for their zealous purging of heretics to be deemed heretical?

There seems to be a lot of issues with the Imperial Fist successor chapters like the Soul Drinkers and Executioners.

Kinslaying usually is just under heresy in such a tight-knit group as a SM chapter, so their crimes had to be truly outrageous . For massacring cities in misguided zeal - I think a Battle-Brother would rather share his doubts with the Chaplain, especially so in case of the the Templars. Not to mention the flamer - destroying a fellow marine's geneseed suggests something far beyond killing civilians.

If I were the player, I'd spin it so that he killed his squad to save them. Maybe some form of possession took them. Maybe they were trapped, and something baleful prepared to destroy their very souls. Go for something very, very sinister and grimdark.

The secondment to the Deathwatch might be a punishment for failure, or some sort of personal penitence for the kinslaying, either dispensed by the Chaplain, or chosen voluntarily. It might be a way for the Castellan to get him out of sight until the dust settles, because his new squadmates, not allowed to know the details, were distrustful towards him. It might be, that the being responsible for the incident was heard to be in the Jericho Reach - the Templars are not participating in the Crusade in force, so he was sent to prove the rumours first, and call his vengeful brothers in.

In short, I'd make him a tragic figure, haunted by inner demons. He needn't be torn and doubtful, if you want a stereotypical Templar - the incident might even reinforce his hatred and zeal. What do you think?

I think that that would be an excellent way to add a bit more roleplay to my shoot only squad.

Also, the reason that there seems to be a lot of problems with Imperial Fist successors is because the good folks at the Black Library openly apologized for hating on the Fellows in Yellow and their kin. Used to be on their blog, but it's gone now =(

I think all the adversities the Sons of Dorn suffer provide excellent narrative potential for character growth. If I ever make a PC, it will be an Imperial or Crimson Fist, with the High Gothic motto "Palma sub pondere crescit" as his personal heraldry

Whose to say his actions were radical? Black Templars are renowned for being very zealous but there is nothing to say they can't ever fal to Chaos. Who knows? Maybe exposed to the warp or deamonic incursion a squad of Black Templars began going full tilt boogie down the Chaos path, sprouting eyestorks, tentacles fangs etc. Maybe they begged him to purge them, maybe he simply acted when confronted with them having been reassigned to the area.

true enough but I would think they would kill themselves at that point, right?
Or a better question would be why they were still allowed to fght if they began mutating, since the only chapter ive ever read about being lax in their purging of mutations is the blood ravens

I would go with "et de pugnis Dorn obtinebit" which translates to "The fist of Dorn shall prevail"

true enough but I would think they would kill themselves at that point, right?

Not necessarily. If they didn't realize it, or were corrupted of mind enough to try and hide it and keep developing it. Chaos is insidious.

agreed if it weren't where would the fun be in fighting it.

Consider the possibility that their Crusader Squad was dispatched to a Daemon World to recover a relic of the Great Crusade. While there, many of his brethren, far less mechanical than he, were slightly more susceptible to corruption. They began to suffer from it.

Black Templar being the righteous zealots they are would be unwilling to put up with that sort of thing. So the squad recovers the relic and falls back to the recovery zone. The squad digs in, and the squad apothecary determines that all of them have suffered corruption except the Techmarine. As the Thunderhawk comes in for the pickup, the squad asks the Techmarine to purge them all and return their Geneseed and war-plate for evaluation and re-use or purification as required. He does so.

How would his Marshal react? I think he'd say "Good job. Now that you've had personal experience with corruption and the sorts of unwelcome tasks that exposure may require, I think you have the experience necessary to cope with unusual circumstances. As it happens, there is an opening in the Deathwatch we need to fill..."

Edit: Of course, that would all be said in tones of barely-restrained fury, and admonitions to not lose one's temper and strike the "weaker" Astartes would follow. I love the Black Templar so much! Just the right sort of angry!

If the Apothecary can determine there's corruption present, there'll be no geneseed extraction, it goes straight to the incinerator. Otherwise it's a good script.

Sounds good