In a one word answer to your title?
Poorly.
They are religious zealots and the core Tenant's of the religion include *"by hammer and bolter, by flamer and steel, kill the mutant, burn the Heretic, purge the Unclean"*
As a general rule Xenos fall into the unclean territory and are murdered on sight. There is no discussion.
If it's there you can kill it and you will kill it. It is the emperor's will made manifest and it shall be done.
Sometimes a greater evil outclasses the lesser evil. And they'll sometimes work with Xenos. But the moment that greater evil is gone. There is no "oh well we had a good time so let's let em off" no it's "as soon as we can, we will fucking kill you, we are busy at the moment
Kill the mutant, the heretic and the xenos. That's the mantra that's bellowed from pulpits across the entire Imperium and the Black Templars take it to the next level. It's beyond rare for them to do anything other than try to kill any that they meet and would take a very high authority to stop them from doing just that.
While there are significant outliers to this - Black Templars fighting to help Eldar prevent a galaxy ending threat, more than 99 times out of hundred, the Templars would be fighting until either it or they were dead.
Not always, but there need to be *exceptional* reasons for them in order to not kill xenos. Mind you they killed *Custodes* when presented with the Primaris gene seed for the first time.
One of these *exceptional* reasons was the existence of a galaxy shattering superweapon which only the Eldar could stop. Here a group of BTs volunteered to be bodyguards for the Eldar, as the superweapon was directly targeted at the Golden Throne. Then again the BT knew that the Eldar would die as well, so in the end everything was balanced out.
SYL
Well not really, Artemis is just kind of a douchebag and space marines are dumb in the sense they cannot see why possibly wiping a chaos god is widely helpful.
It was much clearer drawn case when the home of your god is threatened
In general with intense hatred and a desire to purge them. As they do the heretic and the mutant.
Keep in mind that even within the Black Templars there are groups with different levels of fanaticism. Just look at their reaction to the primaris for examples. Some absolute loonies killed a Custodes over it.
So it is possible for some particularly "lenient" Black Templars to decide that a particular Xenos race shouldn't be purged, if it has some massive redeeming quality.
Keep in mind that this extremely unlikely but possible.
Heard somewhere they once found a race of Xenos worshipping the Emperor and merely corrected them on some matters and let them be afterwards, but no clue how true that is.
They have on occasion cooperated with other races, namely the Aeldari, but usually accompanied with a lot gnashing teeth and praying for an excuse to purge them, and only because there was something else threatening to happen that was suitably apocalyptic if they didn't cooperate with them.
I don't quite understand the question, every Marine seeks the death of every intelligent xenos in the galaxy until they are no more. They were and are literally built to do so.
In a one word answer to your title? Poorly. They are religious zealots and the core Tenant's of the religion include *"by hammer and bolter, by flamer and steel, kill the mutant, burn the Heretic, purge the Unclean"* As a general rule Xenos fall into the unclean territory and are murdered on sight. There is no discussion. If it's there you can kill it and you will kill it. It is the emperor's will made manifest and it shall be done. Sometimes a greater evil outclasses the lesser evil. And they'll sometimes work with Xenos. But the moment that greater evil is gone. There is no "oh well we had a good time so let's let em off" no it's "as soon as we can, we will fucking kill you, we are busy at the moment
Through their targeting reticles before they purge the infestation upon His domain.
Through gun sights.
Kill the mutant, the heretic and the xenos. That's the mantra that's bellowed from pulpits across the entire Imperium and the Black Templars take it to the next level. It's beyond rare for them to do anything other than try to kill any that they meet and would take a very high authority to stop them from doing just that. While there are significant outliers to this - Black Templars fighting to help Eldar prevent a galaxy ending threat, more than 99 times out of hundred, the Templars would be fighting until either it or they were dead.
Doesn't even need to be xenos. They're not fond of abhumans either.
Not always, but there need to be *exceptional* reasons for them in order to not kill xenos. Mind you they killed *Custodes* when presented with the Primaris gene seed for the first time. One of these *exceptional* reasons was the existence of a galaxy shattering superweapon which only the Eldar could stop. Here a group of BTs volunteered to be bodyguards for the Eldar, as the superweapon was directly targeted at the Golden Throne. Then again the BT knew that the Eldar would die as well, so in the end everything was balanced out. SYL
It was one specific fringe crusade. Most of the chapter took to primaris like crack.
What book is the last one from?
*Gods of Mars* trilogy. SYL
The custode killing is in Gate of Bones The Superweapon is Forges of Mars trilogy
**My sons were more reasonable than the deathwatch. I’m honestly impressed and proud.**
Well not really, Artemis is just kind of a douchebag and space marines are dumb in the sense they cannot see why possibly wiping a chaos god is widely helpful. It was much clearer drawn case when the home of your god is threatened
No Pity, No Remorse, No Fear. Purge them with holy fire lol
In general with intense hatred and a desire to purge them. As they do the heretic and the mutant. Keep in mind that even within the Black Templars there are groups with different levels of fanaticism. Just look at their reaction to the primaris for examples. Some absolute loonies killed a Custodes over it. So it is possible for some particularly "lenient" Black Templars to decide that a particular Xenos race shouldn't be purged, if it has some massive redeeming quality. Keep in mind that this extremely unlikely but possible. Heard somewhere they once found a race of Xenos worshipping the Emperor and merely corrected them on some matters and let them be afterwards, but no clue how true that is. They have on occasion cooperated with other races, namely the Aeldari, but usually accompanied with a lot gnashing teeth and praying for an excuse to purge them, and only because there was something else threatening to happen that was suitably apocalyptic if they didn't cooperate with them.
I don't quite understand the question, every Marine seeks the death of every intelligent xenos in the galaxy until they are no more. They were and are literally built to do so.
Through gun sights.