As you probably know, he's the Dread Wolf, Fen'Harel. He created the Veil and banished the other Elven gods beyond it. The creation of the Veil caused the downfall of the Elven civilization, their immortality and all their crazy powerful magic.
His sole purpose since then has been the restoration of the Elves. He gave Corypheus the orb, because he wasn't strong enough to unlock himself yet (but he probably is now after consuming the remnants of Mythal). The whole idea was for Corypheus to unlock it and die in the process, so that Solas could use it to tear down the Veil and burn all of Thedas to ash. He just didn't know that Corypheus happened to be immortal.
So yeah, the ultimate goal here is the complete genocide of Thedas as a result of tearing down the Veil, because that's what's required to restore the Elves. Parts of his personality, such as his compassion for Elves and love for the ancient times, is no doubt real, but I wouldn't put too much stock in the rest of what he says, given everything he managed to keep secret, and the fact that he's an actual god wanting to kill everything.