Have you ever heard the tragedy of Darth Plagueis the Wise?
WOAH WOAH WOAH! They're talking about ME! Darth Plagueis, the Master of Disaster, the Myth of the Sith, the Bullseye of the Dark Jedi! But I wasn't always such a monster. In fact, let's rewind this a bit, all the way back to 1999...
Have you ever heard the tragedy of Darth Childkillerus the Brave?
It is said that he could save a person from dying from a broken heart, and despite the incessant cooing of a droid going "OO-BOO, OO-BOO."
I read something somewhere that described Sheev as having Darth Plagueis in a nearby room slowly dying of poison or something while he was having that conversation with Anakin.
Ah, that sounds about right. Where did you read that? Would that have been from the comics and have ended up on one of the wiki pages?
1. Darth Maul was a tool
2. The Rule of Two isn't a cosmic force, it's a rule. Just because a character says something "Always two there are" doesn't mean it's set in stone and enforced by some galaxy-wide institution. It's a custom. It's a general rule. It's a "way of doing things". One doesn't explode if a third one is introduced to the Dark Side while the first one laughs. It's just a policy amongst the Sith to protect their asses.