I think it would be fun to put that old MoP quote back into context with what we know now.
Wrathion says: It is filled with Titan magic, the language of creation...
Wrathion eats the heart and goes into a trance.
Wrathion says: Oh, I see them - a million, million worlds - glittering in their perfection - but one above all others - oh -
A beacon of light surrounds Wrathion. He rises and speaks in a different tone...
Wrathion says: WE HAVE FALLEN. WE MUST REBUILD THE FINAL TITAN. DO NOT FORGET.
Ra-den says: This twisted world is beyond redemption, beyond the reach of deluded heroes. The only answer to corruption is destruction. And that begins... now.
Ra-den says: Wait! I am... I am not your enemy. You are powerful, more powerful than he was, even... perhaps you are right. Perhaps there is still hope.
But there is a yawning chasm of darkness beneath you mortals, vast, endless, and all consuming. I do not believe that you can correct this doomed course.
But... you have earned the right to try. Farewell.
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I think it is interesting, that Ra-den, prior to the fight, was feeling the exact same feelings that compelled Sargeras to form the Burning Legion.