...But I'd like to know what 'powerful' on a boss monster means. As it seems a 'Demon of Souls' oneshot me with whatever ability (melee?). Also, Those 'imbued', what does it means? %-damage on whatever element the monster does? Crit? Oneshot %?

I'm running expeditions around 142 and sometimes it is running smooth with no deaths and suddenly a boss with whatever(?) modifier seem to oneshot me.
Can I read about those affixes somewhere? And how to play around them?

I like your game, but sometimes I get frustrated.
Thanks in advance.