A planet ruined by terraforming(Some Lore and a planet reveal)

Lore for a planet

Amtor is a habitable, incredibly Droo-like world with oceans of water, a breathable atmosphere, and a two large moons.

Amtor was once a world teeming with alien biodiversity. It had its own alien plants and animals kept safe by a thick atmosphere toxic to droods and seas that would poison you if you went for a swim. It may seem awful, but to the local life, it’s home. They never were aware that one day, it would all change for the worse. An advanced, type 2.5 civilization started terraforming planets for their own purposes, such as agriculture, manufacturing, etc. Amtor seemed like a perfect test subject. The thick atmosphere could easily be converted into something similar to home. The oceans already created basins perfect for water. Unethical terraforming began approx. 50,000 years ago, with no regard for whatever life lived there. The project was completed roughly 30,000 years ago. They started to notice what they did was wrong. They tried hard to fix whatever they could, but it was too late. It was beyond recovery.

We know this due to advanced alien equipment and buildings left behind and vast fossil deposits, as well as written and digital records of the planet’s past. It was always the leading theory that it was terraformed because how would a planet this far out from a dim star be so Droo-like???

Maybe someone will bring it back to its former glory. Only time will tell, we only have around 7 billion years or so (it orbits a K-type star, they live longer than the Sun)