In your darkest hour, when the demons come, call on me brother, and we will fight them together

[MaximillianB]

Hi guys,

I'm ex military, and me and a group of others are organising a gift for a fallen comrade's mother.

On him he had tattooed:
"In your darkest hour
when the demons come
call on me brother
and we will fight them together"

Id be most grateful if any of you could help me by providing a translation of this phrase, it really would mean a lot.

Thanks,

 

[Adrian]

Daemonum Adventu in discrimine versatus
Invoca Me Frater
Una illos oppugnabimus.