Where does that pet orc come from?

[Rafa]

My SpVM has was clearing Vault 8 with the help of some Nemelex summons. Something raised a few corpses, giving me a level-permanent shadow dragon and yaktaur zombie. So far so normal, but I also aquired an orc warrior there. A living, friendly orc guy who seems willing to stick around.

In the mess I mostly only checked that my summons were friendly, can't tell the demon-like stuff apart yet, so I have no idea who or what gave me that orc. There were a few hostile ones around the level, but he has remained friendly for so long I doubt its still from a crusade card. Could someone share an explanation please?

[pratamawirya]

Hey, actually I got a very powerful yet weird pet too in my last game. It was in Zot:5 and I got an Electric Golem after using a Deck of Summoning.

No it wasn't a hostile one turned friendly by Crusade card effect, because the golem disappeared after a while like it was summoned.

[Tiber]

The crusade card has a small chance of making a monster permanently friendly. That's the only way I know of to make an enemy permanently friendly (well, except Elyvilon's power, but that's different). But I'm a newbie (well, a newbie who uses spoilers anyway), so take that as you will.