It was a Galactic event that slowly made the empire that 'had' it get multiplicative with time. It was NOT an item or object I could find but a News blurb which said 'The Yor have discovered a Precoursor relic' they will get bonuses from now till end game....

I ignored this on my first games and wondered why the 'gifted' Race came in so damn strong late game. They had 100's of ships and all techs. It was AMAZING!

Needless to say, I made it my job to hunt down the offending race and eradicate them EVERY game as fast as I could.

Now comes GCIII...

We have 'The Bane'.....

Sounds like a DLC in the making, 

Galactic News Flash..."The Angry Army" has found The Bane on "YorHoochie 3". This race will get progressive benefits and have negative diplomacy modifiers till they are eradicated or lose the 'The Bane'.

Anyway I am just foreshadowing what seems like a DLC or such. 

Thoughts?