User blog comment:Dark Cyan/Cyan's Rap Battles 22: Agumon vs Gon/@comment-25872721-20151003121052

Gon won it for me.

Onto the hint. You confirmed no Iron Man and no Iron Giant.

Other iron related names I can think of include Margaret Thatcher (Iron Lady) and Iron Maiden.

Perhaps the hint is not in the iron, but in the chemical symbol or numbers. Maybe Fe as in Santa Fe? Is Santa going to be in the next battle?

My best guess is Santa.