What the achievement asks
Defeat 8 of the special creatures that spawn during storm events. Account-wide.
The element decides which four can appear
A storm rare spawns inside the storm itself, so what matters is not where you stand but which element is running. Check the live storm, and you know which four names are even possible.
Sixteen possible, eight needed
A rare appears at the start of every Primal Storm, and then again every thirty to fifty minutes until the storm ends. Which one you get depends on the element.
| Firestorms | Sandstorms | Snowstorms | Thunderstorms |
|---|---|---|---|
| Neela Firebane | Grizzlerock | Frozion | Pipspark Thundersnap |
| Kain Firebrand | Zurgaz Corebreaker | Rouen Icewind | Voraazka |
| Emblazion | Bouldron | Leerain | Gaelzion |
| Infernum | Gravlion | Crystalus | Karantun |
The achievement lists eighteen names in total, including Maeleera and Fieraan, and asks for any eight of them.
Since a hotfix they all drop an illusion formula matching their element: Primal Air, Primal Earth, Primal Fire or Primal Frost. Worth knowing if you were going to skip the loot.
Stay for the whole storm
The first rare spawns immediately, so most people get one per storm and leave. Staying gives you a second and sometimes a third from the same trip, which turns eight rares from eight storms into three or four.
It comes free with the other sixteen
Storm Chaser needs you inside sixteen different storm-and-zone combinations anyway. If you stay in each one rather than clearing your imbued kills and leaving, this finishes long before that does.
Where it fits
One of three under Into the Storm, which rewards a Coralscale Salamanther and is a piece of A World Awoken.