Yeah I'm decent at prep but its pretty much me panicking at tornadoes that messes with me. Every time i get it down to around 100-150 hp and the tornadoes come out it gets a bit tense hahah
I am the same, still panic during that phase when there is less room to move around. It's REALLY helpful to start the encounter when Hunllef is in one of the corners of the room, as it means you have more safe spaces to run around from the tornadoes.