abilities
physiological abilities

ENHANCED PERCEPTION » Extremely gifted at picking up on other people's source of powers and detecting various auras. This is both an ordinary skill of perception and a use of his nen abilities. He has been known to pick up on the presence of others even when they have intentionally hidden themselves with their abilities. He has occassionally underestimated opponents.
ENHANCED STRENGTH » Able to open a 64 ton gate and has been seen effortlessly lifting boulders and fighting off four tanks. Strong boy.
ENHANCED SPEED × REFLEXES » Extremely quick and has often killed people before they even realize it. He can dodge bullets and move within the blink of an eye. Fast boy.
ENHANCED AGILITY AND GRACE » Between his speed and perception, Killua has incredible agility and can move himself effortlessly in a battlefield. He has an incredible sense of balance, able to be as much of a threat whether standing on his feet or his hands.
ENHANCED STAMINA » Incredible stamina with him able to run several miles without breaking a sweat. He was in one fight for ten days at a time while maintaining alertness during the brief times he slept.
ENHANCED DURABILITY » While Killua can suffer extensive injuries, he is far more durable than a typical human. An ordinary punch would do absolutely nothing to him. It would require a seriously juiced-up individual to start causing damage through blows.
ENHANCED ENDURANCE » Due to being raised by assassins, Killua has been trained since birth to withstand extensive pain and torture. He has an incredible resistance towards pain, typically not bothering to stop while injured during a fight. He has fallen asleep while being tortured, can dislocate joints without pain, and can prepare plans of action even while undergoing torture.
POISON IMMUNITY » Resistant to a vast amount of poisons and toxins. Some magical based poisons may still impact him.
RESISTANCE TO ELECTRICITY » His family regularly electrocuted him to build up a tolerance against electrocution. He does still feel the pain of electrocution, but this has subsided generally through the focus of his nen abilities revolving around electricity.
ACCELERATED HEALING » Killua cannot regenerate his flesh like Wolverine or anything, but he does have accelerated healing. What would take some people months to heal from would only take him a month or less. Less severe injuries take even less time, such as only a matter of days.
intellectual abilities

GENIUS INTELLECT » Killua is incredibly intelligent for his age and even among adults. He has prodigious intuition and is wildly clever. He's a quick thinker who is capable of assessing his situations regardless of how dire they may be. He is a logical and rational person which has occasionally hindered his ability to read a situation. He is observant and aware of his surroundings at all times which gives him an advantage in most tense moments. He usually picks up on new techniques rapidly, but can express intense frustration if he struggles to be good at something new.
MASTER STRATEGIST » Due to his intelligence, observation skills, and general knack of analytics, Killua is a mastermind at strategy. Even when a plan fails, he's capable of thinking up a new one on the spot.
QUICK LEARNER » What takes people years to learn often only takes Killua a few months or even a few weeks. He is naturally gifted both physically and intellectually and soaks up new lessons like a sponge. Once he has set his mind to learning something, nothing will get in his way of becoming a master over the skill.
MASTER SKATER » Able to perform accrobatics with a skateboard. Boss ass skills here.
MASTER DART PLAYER » A bullseye master of darts. Do not place your bets against this kiddo.
MASTER OF YO-YOS » Yo-yos are the main weapon he uses when he uses a weapon. He is extremely talented with yo-yos and can use them to kill people or interact with items.
assassination abilities

MUSCLE × JOINT CONTROL » Killua is capable of manipulation his joints such as dislocating his fingers in dire situations.
CLAWS » Capable of forming his fingernails into claws that are sharper than knives. These claws can tear effortlessly through human flesh.
MASTER HAND-TO-HAND COMBAT » Excels at hand-to-hand combat. While Killua is capable of using a variety of weapons, his preference is largely depending on his hands and nen abilities.
»» ASSASSIN MODE » A specific mindset that Killua enters that allows him to hyperaware of his enemy. This mindset keeps him from hesitating and puts him in full kill-mode.
»» THE SNAKE AWAKENS » Killua moves his arms so quickly around him that nothing can come into contact him without being cut up in the process.
MASTER WEAPON SPECIALIST » Like any good assassin, Killua is capable of using guns, blades, and a variety of other weapons on an expert level. His weapon of preference are yo-yos.
MASTER OF STEALTH » As an assassin, Killua is a master of concealing his presence and silently gathering intel.
»» SILENT GAIT » Killua can walk and run without making a sound - even those with enhanced hearing can't seem to hear him when he's using his silent gait.
»» RHYTHM ECHO » An artform mastered by the Zoldycks that creates a disorienting "echo" that projects afterimages of the walker. This is intended to make it difficult to tell where Killua's real body is.
»» BLENDING » Can disguise his presence in various locations including nature which has allowed him to get close to a variety of animals most have never encountered before.
nen abilities

NEN » The main source of abilities in Hunter x Hunter is known as nen. This ability essentially allows individuals to manipulate their "souls" or auras/life energy in a variety of ways to use in fights and other tasks. It is an incredibly powerful skill and is a well guarded secret in the world of HxH. Most people do not have nen or any awareness of its existence or how it functions. Killua has been trained to harness his own nen and is highly profeccient in its use.
TRANSMUTER » Nen users are broken down into categories depending on how they can access their nen. Killua is a transmuter. This allows Killua to manipulate aspects of his nen to replicate/mimic other things. Killua mostly mimics electricity. This means that the electricity he uses in fights is not actual electricity, but his actual aura manifesting as electricity. He can use electricity in several ways and the following list some of his most common moves:
LIGHTNING PALM » Electrocuting opponents to push them back with his energy.
THUNDERBOLT » An aerial attack that jolts opponents with a bolt of electricity. This can cause paralysis and pain.
GODSPEED » This is Killua's most powerful skillset wherein he is shrouded in an electric aura. He engages his nen with his immediate surroundings, processing stimuli through electrical currents which allow him to react unnaturally fast to threats. It gives him an incredible advantage in terms of speed and power.
He is extremely fast in this state and it is estimated he can run about 149.1 mph which means nothing to me because I'm a fucking idiot. If he's carrying someone at this time, they will be electrocuted a tiny bit.
overall weaknesses
PSYCHOLOGICALLY VULNERABLE » Killua is mentally vulnerable to psychological attacks whether through power, brainwashing, or basic manipulation tactics. While is generally level-headed and rational, he can also be pushed to emotionally driven choices rather than logically based choices.
GROUND-BASED ABILITIES » Any ability based on the earth/rock will be able to nullify his electrical abilities. This can include other anti-electric means such as rubber.
SHORT CIRCUIT VIA WATER » If Killua is completely drenched from head to toe, he will not be able to use his electric abilities until he has dried. If he is covered in a raincoat, umbrella, or only partially wet, he can still use his ability. He would be able to super electrocute something that is wet, but not actual bodies of water or containers of water.
TRADITIONAL INJURIES » Although Killua has enhanced healing and other instincts, he can still experience broken bones, split skin, bruising, and other injuries. Killua is much more durable than regular humans, but he could still die or be critically injured in a variety of ways.
One simply would have to be quick, strong, and clever enough to hurt him. He's just as vulnerable to a gunshot or decapitation as the next person. His healing does take actual time to occur, so he cannot regenerate in any battle and would need to seek proper medical treatment regardless of accelerated healing.
GROUND-BASED ABILITIES » Any ability based on the earth/rock will be able to nullify his electrical abilities. This can include other anti-electric means such as rubber.
SHORT CIRCUIT VIA WATER » If Killua is completely drenched from head to toe, he will not be able to use his electric abilities until he has dried. If he is covered in a raincoat, umbrella, or only partially wet, he can still use his ability. He would be able to super electrocute something that is wet, but not actual bodies of water or containers of water.
TRADITIONAL INJURIES » Although Killua has enhanced healing and other instincts, he can still experience broken bones, split skin, bruising, and other injuries. Killua is much more durable than regular humans, but he could still die or be critically injured in a variety of ways.
One simply would have to be quick, strong, and clever enough to hurt him. He's just as vulnerable to a gunshot or decapitation as the next person. His healing does take actual time to occur, so he cannot regenerate in any battle and would need to seek proper medical treatment regardless of accelerated healing.