Cleff's Pact.
Cleff's Pact Beast and Pact Price are of his own undoing... For his Pact Price is to constantly gain knowledge of anything and everything through his Pact Beast... However, the more knowledge he gains, the less human he becomes, having no will of his own to use the knowledge he so wanted to attain. So at the price of knowledge, he cannot use it for himself, like he wishes. His body is also changing severely, and his speech patterns are becoming more computerized and robotic, thus he is losing his humanity.
Cleff's Pact Beast is Nirvana, a robot girl about the height of 6 or 7 feet. She is beyond durable, able to take the biggest of hits and repair herself automatically after a time via Hyper Regeneration (if she is to be deactivated). She and Cleff have become lovers, thus creating a sort of special bond between the two that none can break, thus allowing Nirvana to have a will of her own, in a sense. She is incredibly powerful, having the strength to destroy mountains, and comes with a lot of... hidden and useful abilities. She is completely and utterly silent, however, and seems to also be very slow. Her attacks are made by command, the louder the command the more powerful it is. As Cleff loses will, she gains will in exchange for the constant knowledge, and therefore she will soon be able to attack things on her own without use of the commands. Here is what she looks like.
Nirvana's powers are generally based solely off of her extremely powerful strength, however she has slight ability to distort her surroundings to an extent.
Volante: Using an extremely concentrated amount of Seithr, Ars Magis and energy from The Boundary, she combines them all into a black sphere in her hands, in which she will launch at a high speed at her foe. This sphere has the ability to distort the flow of space and time not only around it, but also of what it touches, causing a series of effects... These can range from severely slowing the opponent or paralyzing them, restrict and/or block them of their powers, or even the ability to erase them completely. (For the record, Seithr is extremely toxic to any living being, Ars Magis is a mixture of Science and Magic, and The Boundary is... unknown.)
Allegretto: Nirvana uses the power of Ars Magis to allow her to move at high speeds for a short period of time, allowing her to dash at her foes in powerful bursts. The effect of how much speed varies.
Con Brio: Nirvana reinforces her claw-fingers with Ars Magis, allowing them to pierce through literally any substance whilst this move is in effect. She will then extend her fingers and stiffen them, then try to stab at or cut up the foe, usually locking them in a gridlock fashion between her fingers.
Con Anima: Nirvana focuses all of her power as well as Ars Magis into her arms to grab her opponent and crush the life out of them, blocking their powers once they are touched as well as severely weakening them as long as they are being touched by Nirvana so that she may crush them with ease. Not only this, while this is in effect, any applied force or pressure to get out of her grip is then take and doubled so that she may ensure that they stay there.
Con Fuoco: In the same sense of Con Brio, she reinforces her claw-fingers with Ars Magis, allowing them to pierce through literally any substance whilst this move is in effect. She will then rotate her hands and stiffen them into the shape of drills, drilling through everything she can.
Fermata: Nirvana delivers an extremely powerful uppercut using all of her power plus the force of anything that has hit her in the current battle. The uppercut has so much power that it can take down damn near anything (if Nirvana has taken a lot of force). It is known as the planet-destroying fist.
Rhapsody of Memories: A violent, all out attack using all of her strength as well as reinforcement of her entire body with Seithr and Ars Magis to make herself at maximum power. She will then begin to destroy everything that she possibly can around her, leaving nothing. A berserker attack.
Deus Ex Machina: One of her most powerful attacks, in which she initiates her self destruct sequence from a countdown of 10. If not stopped within those 10 seconds, she will proceed to explode, the explosion able to take down everything with the strength of several nuclear, atomic and hydrogen bombs combined. She is then completely and utterly drained afterward, and must go under several hours of Hyper Regeneration to be functional again.
Laetabillis Cantata: Nirvana's most powerful ability, in which she actually uses the power of Seithr, Ars Magis and The Boundary to transport herself and anyone within a certain radius of her into another plane of existence that is severely distorted. What will appear before Nirvana will be 3 astronomical, layered gears, one in side of the other. These are the Gears of Fate, Time and Reality, also known as the 'Wheels.' They are only able to be accessed by Nirvana, and will spin around profusely, trying to take in whatever Nirvana has brought to this realm, and if they are touched, then the Gear of Fate will destroy their fate, the Gear of Time will destroy their time, and the Gear of Reality will destroy their Reality, all 3 being key components of life. Using this severely drains Nirvana and she must recharge for several hours after use.