If this is gold rush, just go to the middle and mighty guard + diamondback before the cast completes. You’ll get like 5 vuln stacks and need to move behind him when diamondback wears off because he does two beams at the end. His autos don’t hurt enough to worry about even turning mg off afterwards, although you’ll probably need to heal twice. Healer mimic and Pom cure would be easier on your mp than white wind.