With the world first victory over Mythic Fyrakk, the world first legendary axe Fyr'alath, the Dream Render has also dropped directly from the boss! While we wait for more information, it looks like the item drops directly, though it appears to be unequippable until completing a quest, similar to crafting up Nasz'uro, the Unbound Legacy for Evokers.
Interestingly, the axe also doesn't appear to be personal loot either, as the explosion of excitement and energy after the world first kill resulted in most of the players passing, with the weapon ultimately looted by Meeres.
Who got the legendary?!
It's unclear what this means for the rest of the world, if the weapon is indeed meant to only drop on Mythic difficulty, or whether it will also unlock for players on lower difficulties after the next weekly reset, the same way Nasz'uro did in Patch 10.1. As for the effect, there's very little information on that yet either — the on use effect simply reads: Wield the might of The Blazing, becoming enveloped in its Shadowflame. This also restricts it from being wielded, as attempting to equip the axe literally envelops the player in Shadowflame — beginning the legendary questchain.
Attempting to equip the weapon goes badly, but begins the legendary questline to claim its power.
We're sure to find out more in very short order, though it's also interesting to note that the available classes includes a mysterious «Adventurer», but this is probably just a leftover internal test setting on Blizzard's part.