After a while, Raszageth afflicts four players with either Mark of the Wind or Mark of the Lightning, increasing their damage and healing by 15% for 15 seconds.
However, the marks must be cleared shortly before the 15 seconds expire by coming into contact with the opposite mark to remove the debuff. Otherwise, they will cause a Primal Overload which stuns players for 8 seconds and deals Nature damage.
The marks will always apply to all damage dealers in your group.
If you currently die in the middle of a pull and run back, you might get affected by the mark and die before you reach your group, which isn’t ideal. Hopefully, the affix will be overhauled in future Dragonflight Beta builds.