Byte

"No! How can this great power be generated from within an ancient machine!? Well done X. The victory is yours."

- Byte to X if he is defeated with his weaknesses

Byte, known as Mandarela BB (マンダレーラＢＢ) in Japan, is a member of the Nightmare Police, along with his partner Bit, being the strongest of the pair.

Mega Man X3
After the defeat of two from the eight bosses, Dr. Doppler orders them to take X for him, alive if possible. After the defeat of Bit and a few more bosses, Byte will appear as a sub-boss in the stages until he's defeated. If he's defeated without using his weaknesses, he will retreat, dying only if he's defeated with Tornado Fang or Ray Splasher. If Byte survive, X will have to face him and Bit again in the first Doppler stage, where they will combine into Godkarmachine O Inary. If only Bit or Byte survive, they will still be able to transform into Godkarmachine O Inary.

Byte mainly attacks by throwing his hands and moving toward the launched hand.

Rockman X3 manga
In the Rockman X3 manga, Bit and Byte are the Nightmare Police created by Doppler. Their bodies are made of several small worms made of chips that can turn Reploids into Mavericks. They attack the Maverick Hunter's base and fight against Zero, Blast Hornet, Blizzard Buffalo, Tunnel Rhino and Neon Tiger, having advantage in the battle despite being outnumbered. After X's recovery, he goes to the battle and destroys Bit's shield and arm with one charged shot. They decide to retreat after this.

After the defeat of all the eight Maverick bosses, they make an announcement in the Christmas Eve to challenge X and Zero. Bit and Byte manage to defeat them with ease, capturing and locking them into a powerful drilling machine that would kill them, showing it on a screen in Doppler Town. Dr. Cain and Marty went to the rescue, Cain and Marty's pirates distracting Byte and several Mavericks while Marty goes save X and Zero with four power up chips. After obtaining the chips, X gained a powerful armor and shot at Bit, causing high damage to him and destroying several Mavericks that where at distance with Byte. Seeing this, Byte returned to help Bit and Doppler appears with a dragon made of his chip worms. Byte asks Doppler to help Bit, but he makes his dragon attack with a powerful blast in the area X and the others where, the attack hitting Bit, Byte and Zero, which don't had time to avoid it. Damaged, Byte asks Doppler to give them a chance to defeat X, and he drops several worms to combine them into Godkarmachine O Inary. They became more powerful in this form, but none of their attacks works on X. X took down both Godkarmachine O Inary and Dr. Doppler's dragon with one shot. As a last attempt to defeat X, their remains merged into a giant two-headed multi-limbed worm-like monster, but it collapsed before it could attack because of the damage they had received.

Quotes

 * "Affirmative, Dr. Doppler!"
 * "Nice to meet you, X. I am Byte. I've been programmed to exterminate you!"
 * "I didn't expect you had this power... I've lost this time but... I'll crush you next time!!"
 * "No! How can this great power can be generated from within such an ancient machine!? Well done X. The victory is yours." (Death; defeated with weakness.)
 * "Dr. Doppler modified us after our first battle against you." (Doppler's Lab with Bit.)
 * "Take a look at these new upgrades!" (Together with Bit, before Godkarmachine O Inary transformation.)
 * "X, I've been waiting for you. It was an impressive victory over Bit. Unfortunately, it was your last!!" (Doppler's Lab alone.)

Trivia

 * The name of the Nightmare Police members comes from bit and byte, two units of digital information in computing and telecommunications. Byte's Japanese name is derived from Mandala, a concentric diagram having spiritual and ritual significance in both Buddhism and Hinduism.
 * His appearance is seemingly based on Nio.