Well, I appreciate you getting up off the floor, and tearing yourself away from your coloring-books to tell me this.
If Canonically from an in-universe historical-standpoint, Sidious was supposed to be the most powerful Sith Lord ever known, then Vader would likely know his Sith history and would indeed know his Master as the most powerful Sith Lord in history.
Add to the fact that his Master had also managed to take down the Republic and annihilate the Jedi Order, as well as defeat Grandmaster Yoda.
Vader knew, and his lines in ESB reference this somewhat subtly, that his Master was the most powerful Sith Lord that history knew.
Because for all intents and purposes - according to what history remembers - he is.
Vader already knew his Master was the most powerful according to what history could remember. It likely wouldn't remember Nihilus anyway, since he was essentially a rogue Sith Lord who kept a low-profile even when he was "alive", and after he died, there isn't good evidence to suggest the Jedi Order (much less the Republic) knew of, or could remember his existence, afterwards.
Especially for you.
Stealth Moose is as cool as the other side of the pillow, and besides, alot of the other Debators on here who are extremely skilled and adept usually have similar opinions to mine, anyway. It's not unusual.
I think your unfinished coloring-books are calling to you..
They beckon and besides, I think your mom just left a flesh plate of hot goey chocolate cookies there - you better go investigate.
__________________ There are no contests in the Art of Peace. A true warrior is invincible because he or she contests with nothing. Defeat means to defeat the mind of contention that we harbor within.
- Morihei Ueshiba
__________________ There are no contests in the Art of Peace. A true warrior is invincible because he or she contests with nothing. Defeat means to defeat the mind of contention that we harbor within.
- Morihei Ueshiba
__________________ There are no contests in the Art of Peace. A true warrior is invincible because he or she contests with nothing. Defeat means to defeat the mind of contention that we harbor within.
- Morihei Ueshiba
__________________ There are no contests in the Art of Peace. A true warrior is invincible because he or she contests with nothing. Defeat means to defeat the mind of contention that we harbor within.
- Morihei Ueshiba