Hyper Knuckles

Hyper Knuckles (ハイパーナックルズ) is Knuckles the Echidna when he taps into the seven Super Emeralds and 50 power rings or the Master Emerald. He has increased speed, strength, endurance, and a devastating tremor attack that destroys everyone in sight. Like his Super transformation, he pulses from red to pink. Unlike his Super form, any movement he makes leaves afterimages. His only game appearance was in Sonic 3 & Knuckles, but he has made a couple of appearances in the Archie comic book series fighting several enemies like Super Sonic, Robotnik, and Mammoth Mogul. However, it should be noted that in the Archie Comics, Hyper Knuckles was his given name for Knuckles' 7 Chaos Emerald Super form before eventually being retconned into being called Super Knuckles.

Archie Comics
In the Sonic the Hedgehog series from Archie Comics, Knuckles first achieved his Hyper form when a confrontation with Sonic the Hedgehog pulled them both into another Zone from that of Mobius Prime. Having collected seven Chaos Emeralds and fifty Power Rings each, both fighters transformed into their advanced forms. After a brief battle, the two were expelled from the Zone and powered down, though Knuckles got a backup Chaos Emerald for Angel Island out of the struggle. (SvK)

Some time later, he would use this form in a battle with Master Mogul alongside Super Sonic and Turbo Tails, using Mogul's Emeralds and Power Rings provided by the Ancient Walkers to power up. In the resulting battle, Mogul became imprisoned in the recently created Master Emerald. (StH: #56)

A year later, after losing his Chaos powers due to returning from the afterlife, Knuckles would use the Master Emerald to take this form again without the aid of Chaos Emeralds, this time calling it Super Knuckles, as he did battle with the villainous Hunter, eventually throwing him off Angel Island and killing him. (StH: #125, #141)

Abilities
Hyper Knuckles has many abilities such as, while in Hyper Knuckles form, Knuckles' natural abilities are multiplied many times over. His already impressive strength and speed increase, and he also becomes virtually invulnerable so long as the transformation lasts. Also, when Hyper Knuckles glides into a wall, he causes an earthquake that destroys all enemies on the screen. Knuckles' natural bond with the Chaos Force is also more open to him while in this state, granting him abilities he would not otherwise be able to utilize.