is a currency introduced with the Blackrock Eruption event in Season of Discovery Phase 4. This currency can be earned through completing Daily Quests during the event and has primarily been used to upgrade Fire Resistance gear.
Blackrock Eruption Event Guide
It was recently announced these will stack to 2500 and Developers Noted that you should hold on to them.
With the Phase 5 PTR now underway, players have visited the Firelands Ember vendor and shared some new wares discovered.
Image Shared on the WoW Economy & TSM Discord Server by user: eightySix
While the prices are high and there are likely more efficient ways to farm these items, this does provide players with a great option to spend extra Firelands Ember, once Fire Resistance items have been upgraded.
Other trade goods have been made available through the Emerald Wardens' on the Season of Discovery, Phase 5 PTR.