From Wikipedia......
IRON FIST:
(Powers and abilities)
Plunging his fists into the molten heart of the dragon Shou-Lao the Undying infused the dragon's superhuman energy into Rand; this along with training by Lei Kung the Thunderer gave Rand the power of the Iron Fist, allowing him to summon and focus his chi (or natural energy) and enhance his natural abilities to extraordinary levels. His strength, speed, stamina, durability, agility, and reflexes and senses can all be astronomically intensified, making his already formidable martial arts skills even more so.
The ultimate expression of this focus is the ability to concentrate his body's natural energies into his hand, manifesting as a supernatural glow around his clenched fist, making his fist "like unto a thing of iron." So concentrated, this "iron fist" can smash into its target with superhuman hardness and impact, while his hand becomes impervious to pain and injury. However, the feat of summoning the power required leaves Rand physically and mentally drained, unable to repeat the act for a time, as long as even an entire day in certain instances. Such an ability is described as "quasi-mystical".
Other applications of the Iron Fist power include the ability to focus chi energy inward to heal oneself or outward to heal others of injury, as well as the ability to telepathically fuse his consciousness temporarily with another person and meld with that person's mind. In Maximum Carnage, Rand was able to use the mental application of the Iron Fist to temporarily calm a rioting mob. When asked about this by Spider-Man, Rand replied that all humans are, in essence, one divine being, in a constant craving for that oneness, and once it is offered, it cannot be refused. When asked by Spider-Man how long it would take to learn this "meditative technique", Rand replied, "Eight or ten years."
Orson Randall, Rand's predecessor as Iron Fist, demonstrated applications including hypnosis and channeling his chi energy into projectile weapons to increase their destructive capacity. Randall also showed enhanced resistance to injury, including resilience to poison gas dropped on his fellow combatants in the trenches of World War I, and a greatly slowed aging process. Although almost one hundred years old by the time he encountered Daniel Rand, he demonstrated physical vitality commensurate with a highly-trained martial artist half his age. Rand has presumably acquired powers and abilities at least equivalent to Orson Randall's — though not necessarily the skill to control them — thanks to combining Randall's chi energy with his own. He is also in possession of the Book of the Iron Fist, study of which will greatly expand his kung fu skills.
Rand displayed what he had learned from Orson Randall regarding alternative applications of the Iron Fist when he was able to extend his chi from his fist into the electromagnetic field of the train intended to destroy K'un Lun, transforming himself into "a human bullet." Despite the train being loaded down with "enough raw explosives to make Hiroshima look like a sparkler", Rand was able to destroy the train, and survive the massive explosion virtually unharmed.
Even without the Iron Fist, Rand is a master of all of K'un Lun's martial arts and many of Earth's, making him easily one of the most skilled practitioners of unarmed combat in the Marvel Universe.
In a confrontation with Tony Stark, it is revealed that Iron Fist has been registered as a lethal weapon, as is supposedly required of advanced martial artists in the United States. His lawyer is present during the confrontation and argues the loophole that he is already registered with the government, and that his abilities are skill based and not power based, meaning that he does not technically qualify as a superhero and it is suggested that he has broken no laws.
NIGHTWING:
(Powers and Abilities)
Nightwing possesses the peak athletic strength and endurance of a man in his mid/late twenties who regularly engages in intensive physical exercise. His martial arts skills rival those of Batman. He is a master of dozens of martial arts disciplines and was rigorously trained by his mentor in everything from escapology to criminology, fencing, stealth, disguise, and numerous other combat/non-combat disciplines.
Nightwing is a master of a half-dozen martial arts disciplines (including aikido, savate, judo, and capoeira) with an emphasis on aikido, as well as being armed with twin Eskrima sticks made from an unbreakable polymer. He also carries several dozen modified batarangs (called wing-dings) along with de-cel jumplines and gas capsules.
Grayson is a prodigious natural athlete, possessing a peak human level of agility/acrobatic skills. He is generally regarded as the greatest human acrobat in the DC Universe. He is the only human on Earth who can do the quadruple somersault (formerly one of three, the other two being his parents). Having had the finest education as Bruce Wayne's ward, he fluently speaks in English, French, Spanish, Russian, Mandarin, Cantonese, and Japanese and has some knowledge of Romany, the alien language of Tamaran, and American Sign Language. He is also a brilliant and experienced strategist with superlative leadership skills, having served as leader to the Titans, the Outsiders, and even the Justice League. Additionally, Dick's interpersonal skills and efforts to remain in contact with other heroes makes him a master at rallying, unifying, and inspiring the superhero community, a skill in which he has surpassed his mentor.