Super Knuckles

Super Knuckles (スーパーナックルズ) is a transformation that first appeared in Sonic & Knuckles. It is the Super State of Knuckles the Echidna, achieved by harnessing the power of the seven Chaos Emeralds.

Appearance
When transformed into Super Knuckles, Knuckles' physical traits remain unchanged. Instead, he gains a pulsating golden energy shield around himself.

In the Sega Mega Drive-based games, Super Knuckles' fur pulsed in a bright magenta color and he possessed a magenta colored aura. However, he lacked any form of a shield.

Sonic the Hedgehog 3 & Knuckles
Super Knuckles first appeared in Sonic & Knuckles and its extension Sonic the Hedgehog 3 & Knuckles. The transformation can only be obtained by collecting the seven Chaos Emeralds as Knuckles. The player can then activate Knuckles' Super State by collecting fifty Rings and then press the jump button twice. While Knuckles is transformed, the player's Ring count drops by one Ring every second. When the Ring count hits zero or when the Act Boss is defeated, the transformation runs out.

In gameplay, Super Knuckles is invincible, can move, glide and climb faster, and jump higher. In Sonic the Hedgehog 3 & Knuckles, should the player enter the neon flashing giant ring in Mushroom Hill Zone, the player will have their Chaos Emeralds turned into Super Emeralds in Hidden Palace Zone, thus preventing Knuckles from becoming Super Knuckles anymore. By collecting Super Emeralds though, the player is able to transform Knuckles into Hyper Knuckles.

Knuckles the Echidna in Sonic the Hedgehog 2
By locking-on Sonic the Hedgehog 2 and Sonic & Knuckles, the player is able to get normally Super Knuckles in Knuckles the Echidna in Sonic the Hedgehog 2 by collecting the seven Chaos Emeralds. In gameplay, Super Knuckles' abilities are identical to that in Sonic & Knuckles. Like before, the player's Ring count drops by one for every second Super Knuckles is active. When it reaches zero, Knuckles reverts back to normal.

Sonic Heroes
In Sonic Heroes, Super Knuckles appeared as the Power Type member of Team Super Sonic. When Metal Overlord took off, Sonic transformed into Super Sonic and shared his chaos energy with Knuckles and Tails, allowing them to achieve their own Super States and go after Metal Overlord together. With the power of teamwork, Team Super Sonic defeated Metal Overlord.

In gameplay, Super Knuckles cannot take damage and he has automatically obtained three red Power Cores. Unique to Super Knuckles, his Volcanic Dunk attack has been changed, enabling him to throw fireballs in front of him over a long range to attack targets. During the boss battle, the player's Ring count drops by one every second, and when it runs out, Knuckles and his team revert back to normal which will cost the player a life.

Sonic Chronicles: The Dark Brotherhood
In Sonic Chronicles: The Dark Brotherhood, Super Knuckles was referenced in the Chaos Emeralds' entry in the codex, where it is stated Knuckles is among many of the people how have used the Emeralds to attain a Super State.

Sonic the Hedgehog (1991)
In the 2013 re-release of the original Sonic the Hedgehog, Super Knuckles can be unlocked as a bonus feature in the gameplay for Knuckles. On Level Select, the player can change the Max Emeralds setting from 6 to 7 to get all seven Chaos Emeralds. After that, the player can use Super Knuckles in any of the Zones with Knuckles after collecting fifty Rings. His appearance is almost identical to his original one from Sonic the Hedgehog 3 & Knuckles.

Super Knuckles' abilities are the same as in Sonic the Hedgehog 3 & Knuckles. Like before, the player's Ring count drops by one for every second Super Knuckles is active. When it reaches zero, Knuckles reverts back to normal.

Powers and abilities
Due to being infused with the seven Chaos Emeralds' power, Super Knuckles accordingly commands ultimate power and has access to unlimited energy. As Super Knuckles, Knuckles' innate abilities far surpasses his normal ones. His trademark strength has been enhanced to the point where he can smash a ship from the Eggman Fleet with a single strike and throw punches so powerful that he creates fireballs which explode upon impact. Knuckles also becomes fast enough to keep up with even Super Sonic who can move at approximately the speed of light. His reflexes are also improved, allowing him to keep up with his increased movements. Like the traditional Super State, Knuckles gains new abilities in this form, including high-speed run-flight and virtual invulnerability to harm.

All of Super Knuckles' standard techniques has been greatly enhanced following his transformation; his Volcanic Dunk technique has been upgraded to the point where he can shoot a barrage of explosive fireballs at his foes, and Glide and Climb techniques can be executed on a much faster rate.

Weakness
Super Knuckles can only stay transformed for a short time without sustainment, as a Super State consumes tremendous amounts of energy. Extensive usage will also put him at risk of disappearing entirely.

Archie Comics
In the Sonic the Hedgehog comic series and its spin-offs published by Archie Comics, Knuckles' Super State was dubbed "Hyper Knuckles." This was because he was set up to battle Super Sonic, and the writers wanted to avoid the monotony of two supers against each other. However, this form would be referred to as "Super Knuckles" later on.

Knuckles' first known transformation was when he went head-to-head with Super Sonic in a battle for the Chaos Emeralds. Knuckles later turned into Hyper Knuckles again to battle Master Mogul alongside Super Sonic and Turbo Tails. Knuckles later obtained his super form again to fight Hunter on Angel Island, this time using the power of the Master Emerald.

Trivia

 * Knuckles' All-Star Move in Sonic & Sega All-Stars Racing and it's sequel - "Emerald Power" - causes Knuckles to use the power of the Master Emerald to take on a state similar to Super Knuckles, albeit with a green energy shield instead of a yellow one, and a green energy trail.
 * Prior to Sonic Heroes, Super Knuckles, unlike most other Super States, does not have a golden glow, but rather a magenta colored one.