The Reason Zenos.

[Jennah]

Technically, Omega survived. Unrelated to Zenos, but thought I'd point that out.

Also Gaius. And Nero. And the Voidwalker. And the Cloud of Darkness. And a bunch that were just testing us, like Midgarsormr, and Hrasevalgr, and Alexander. And pretty much none of the primals were destroyed, just unsummoned for a bit.

Our track record's actually not that great, versus enemies capable of speech.