Background detail suggestion

[Bober]

Hello! I need a little suggestion about something regarding my background. Here's what you need to know:

- He's a Minotaur with both Barbarian and Fighter classes.
- He has a split personality: one docile and nice, and one aggressive and kinda crazy
- He used to work with Dwarves in the mines. The reason is still to be decided [SUGGESTIONS APPRECIATED]
- An accident occurred in the mines, and because of him someone died. It has something to do with his second (aggressive) personality; it's the first time he experience this side of himself (which is where his barbarian's Rage comes from). The accident details are still to be decided.[SUGGESTIONS APPRECIATED]

The rest is not important right now.

The concept is the following:
- While working, something triggered his second personality. That same thing is what is going to trigger it in the rest of the campaign.

I would love some suggestion or advices regarding WHAT COULD BE THE TRIGGER.[SUGGESTIONS NEEDED]
I thought about a word; it would be common enough so that he/it could be trigger in any moment, but I couldn't think of any good one; if it was a common "mining" word, it would have happened during his first week there, and if it's something too sophisticated, it would never happen again. Also, it would be way too easy for a party member to understand what the trigger word is, after just a couple of times.. meaning they could use it all the time, and that's not something we want.

NOTE: The party members do know about this split personality, but do not know what triggers it.

Then I thought about an object maybe.. Something another Dwarf had, or was doing..

So the point is, the trigger has to be common enough for the GM to be able to use it without having to go out of his way, but hard enough to notice so that other players can't use it (or at least not without putting a lot of work into figuring it out) at their advantage.

If you have any idea, please share!

[avr]

Maybe there was a collapse in the mine, he went in to rescue the miners and freed one by lifting a timber off her with a great surge of strength - but she dived back in to retrieve something, maybe an heirloom and died in a further collapse.

Possible triggers from this: axes like the heirloom, collapses and explosions, people doing suicidal things.

[Pizza Lord]

His family was butchered by mercenaries and one of the last things he remembers before he was clubbed and stuffed into a sack was the callous sound of someone saying, "Loot the bodies!"

Sold to a dwarven caravan as a slave, he was freed and raised as a miner by generally good parents one assumes, or at least not mistreated. Well, one day, the dwarven miners encountered some goblins deep in the mines sabotaging tunnels (the accident). The dwarves handily defeated the menace and then one said, "Loot those corpses, they probably have some stolen gems." Well, minotaur secondary personality resurfaced and he kicked that dwarf into a chasm.

So now, whenever someone greedily or callously says something like "Loot the bodies" or "Loot the corpse" he flies into a homicidal rage. But how often could that possibly come up...?

[Bober]

Thank you both for our suggestion, both great! I think I'm gonna steal a bit from both :)

I love the idea of him being sold as slave, but raised as free. I'm definitely gonna use that. I do like the idea of the trigger being linked to his past before the dwarves, but I don't think it would work well with that phrase. Mostly because I would become aggressive any time we loot an enemy, and would just seem like greed..

I like the collapse/explosion as trigger; I could make it a bit more common by making any unexpected loud sound become the trigger. That could help my GM come up with stuff that would trigger it.

The goblin attack could have caused a collapse, or maybe the caused an explosion to ambush the Dwarves from another tunnel.. That would have triggered the personality, and we know how it ends from there..

Thank you both again, my character owes you ;)