Return of Reckoning

Anyone knows where this tonic comes from? ---> "Lasting Zephyr Tonic: Morale is building 25% quicker"
Maybe someone is tempted to say "from some event", but neither I nor anyone I have asked (and i have asked A LOT of people) remembers that this tonic was a reward for any event.

The devs renamed the item samogon, but the buff still has the name from live. Yes, it comes from an event and you can usually find it suitably overpriced on the AH.

Nice, thank you!