While Iron Fist is already a G based on his supreme kung fu abilities, that combined with the power of the Iron Fist make him a formidable threat. The key is that he's able to focus his chi (aka his natural energy) to help max out the skills he already has. Iron Fist has been known to focus that energy into his fists, giving it a "glow" that not only adds impact to said fist, but makes that fist impervious to pain or injury. He's even been known to heal others using this power.

Why this is important: While most of the Netflix Marvel series involve characters with powers they can't really turn off, this is the first time we're seeing one of these heroes who can seemingly go back and forth. He's not ALWAYS the Iron Fist, but when he turns that on, it's a problem. Also, it'll be interesting to see how Marvel translates that "glow" on screen.