You can only fight him on crafting/gathering jobs, the boss does not do normal hits, it has an ultimate move called "mathematical accuracy" that it uses every 5 minutes. The crafters have a core node they must use synthesis actions on and the HQ progression must be 100% before the progression bar deals damage. If you use Steady Hand 2 + Hasty Touch and fail 3x in a row the node becomes invincible for 1 minute. The bot/min have "joint nodes" to hit, if they miss on a 95% gather rate chance the boss gets an attack stack buff for it's ultimate attack. Fisher's can't do a thing, the RNG boss causes them to have permanent terror effect. The only way to break terror is to equip a tackle box in the offhand slot.