With the start of The War Within Season 1, players can farm Stonevault on Mythic difficulty for a chance at the Stonevault Mechsuit mount. This mount only drops on Mythic difficulty and above, so it was not able to be farmed in the pre-season as dungeon difficulty was capped on heroic.
If you are interested in collecting more mounts, check out our TWW Mount Guide detailing the 37 new mounts added with expansion launch!
Stonevault Mechsuit is from the quest Malfunctioning Mechsuit which drops from Void Speaker Eirich on Mythic Stonevault. However, when this dungeon moves out of the seasonal rotation, you will not be able to farm the mount as Mythic difficulty is only available for seasonal dungeons.
What about Wick's Lead?
While Wick's Lead is another drop from TWW dungeons, you cannot acquire this mount in Season 1. This is because Darkflame Cleft is not part of the Season 1 rotation, so you cannot access Mythic difficulty. When it is added to the rotation in a future season, then you can farm this mount.