Beat the Iron Giant tonight,
Bit dissapointed, i think i was too prepared!
All at lvl 99 with 9999HP (tried at lvl 85 lasted about 15 mins lol)
All as onion knights, with onion armour and shields (no gauntlets tho

)
Sent my party to the rear and casted flare, occasionally mixing in a curaja, and elixirs to top up my MP.
The only real threat was his slice attack taking around 3500 off each character, nothing a curaja wont fix tho!
Meteor did 0 damage and his standard attack did around 800!