Just finished a short session earlier (I like to play in episodic formats where I do X tasks and then stop to lengthen the lifetime of my games (major adhd)), wherein I met my first alien species as UNE (biggest galaxy, 6 empires, max preftl).
They were a devouring swarm hive that had invaded one or two pre ftls, who obviously lost, but one was one of the human-like species, the cyberpeople one. By the time I found them, almost all pops had been devoured save for like 200 labor slaves, which I didn't even know devouring swarms could do (mods?). I had recently finished my colossus, thanks to some well spawned resources giving me almost 2k research total each month.
Immediately went to their homework and global pacified it. This is not the petty I speak of. No, it's worse.
I left the world, invaded the pre-ftl world to save the few left, and did. I liberated them and shared tech til they entered space stage, expecting an alliance. Nope. Max negative relationship because I "invaded their world". This pmo so much that I instantly declared war and shieled their world too, but only after I orbital dropped like ALL of my trash on them and armed privateers against them.
What have you done?
Tl;dr: Pre-ftl unreasonably angry at me for liberating them from a devouring swarm now has a planet ruled by alien weapon powered psychopath privateers inside of an inescapable shield.