Vaethria, where would you put Algalon in your list? He is not an end boss,but I feel he is a powerful-enough entity to merit listing among the rest, no?
Edited in below;
Algalon the Observer
Ossirian the Unscarred
The Titanic Watchers (all bosses in Vault of Archavon)
You placed Anub'arak above Gruul? The dude tears dragon's out of the sky like it's no big deal. And Vashj above the titanic watchers like Thorim?? Why is Kael'thas ranked so high as well?
What are the reasons, justifications for you list? Just curious.
A bunch that you didn't ask for are on the first page, too, so you know.
As to yours...
Gruul took down drakes. The same kind of drakes that got killed by Alliance Gryphon Riders all throughout the Second War. "Dragonkiller" is just a badass epithet; he didn't take down any full-grown dragons on the scale of Deathwing's brood (such as Onyxia, Nefarian, or Deathwing)
He was really really strong, but not that awesome.
Anub'arak was a sorcerer-king
of the Nerubian people. The Nerubians are one of the three most ancient civilizations on Azeroth; if any race would have the knowledge required to give their leader incredible control of magic, it would be them.
Anub'arak wins. :P
Vashj is ranked high because she's old enough to have fought in the War of the Ancients
. She's literally had over ten thousand years
to work on her skills, and her magic; something very few others on the list have had. Her in-game presentation was, I'd say, an understatement of her true abilities.
As for Kael'thas, he was the most powerful mage that Quel'thalas had produced since his father - and many centuries younger. Then
he took up with Kil'jaeden, and gained a lot
more power. When the Eredar Lord of the Burning Legion is acting as your personal endorser
and giving you magical power
in exchange for your service, your abilities are going to curve upwards rather sharply in a rather short period of time.
Basically, Kael was all hopped-up on super-demon-juice, making him more powerful than he otherwise could have ever hoped to be. :P
The Watchers are where they are because, despite their obvious level of power, they were intended as observers
, not defenders
. Titanic constructs have shown a distinct tendency towards remaining neutral in as many matters as they can, only acting in either self defense or in direct
action against the Burning Legion or the Old Gods. Yes, they're powerful, but they don't constantly
strive to gain more power, as almost all those ranked higher than them on my list do.
The Watchers are basically created at a given power level, and stay
at that power level - or even lose some of it - while everyone else is constantly after more
power. Hence, they get surpassed.