First of all this requires an immunity to magic of some sort i.e. Bubble, Ice block, Cloak etc.
As your raid is stacking for the second scorpion (third shapeshift) phase to activate searing seeds you are to use your immunity. Do not wait until after you stack and the seed is placed on you because getting rid of it with an immunity causes it to explode. If you time it right you will be immune to Searing Seeds as Majordomo places one on you and you can tunnel vision the entire phase without worrying about running away.