Plagueis

Darth Plagueis became obsessed with the idea that he’d grown too powerful and that the Force would one day betray him for abusing his control over life and death.

As we watch the Stranger talk about how he's searching for the power of two and a pupil in "Teach/Corrupt," there is nothing to suggest that this isn't actually Darth Plagueis or even Darth Tenebrous.

If you want to see a show about Plagueis and a young Sidious, you should write it!

In this moment, with the future of Darth Plagueis's story hanging in the balance, I almost feel like Anakin Skywalker after Palpatine asked if he'd ever heard the tale and Anakin tells him no.

It could be the case that Darth Plagueis has simply been watching this entire time.

It was creating an entirely original story with brand new characters and mere seconds of a few well-placed cameos from Yoda to Darth Plagueis by the finale.

All Palpatine really said about Plagueis was that he found a way to cheat death.

With that said, the Emperor's first mention of Plagueis to Anakin in the films implies many years have passed since the Sith Lord was killed, although it's perfectly plausible the villain might've stretched the truth to make his pitch more appealing.

He respected and admired Plagueis for his ambition and the invaluable knowledge and power he'd passed down.