We keep it simple and easy. This is all you need to know:
#1 Atramedes uses an attack called Searing Flames, which can easily wipe the raid with it's AoE damage.
When he starts this ability, someone needs to use a gong to interrupt him.
#2 Atramedes has a flight phase where he will drop bombs. They do AoE damage, so stay away. Don't waste gongs during flight phase unless you're about to die.
#3 Atramedes uses an attack called flame breath, where he spins around, drowning the raid in flames. This is easily avoidable if you just run accordingly