Antares.

Antares: [N-BOSS] HP: 2,000,000/2,000,000. Ages II. Ancestral III. Agreement Inapposite IIII. Cthk'aryvtian Servitude: IIIII.

Ages: Antares infuses Valedrius with time itself, and impales an entity. Said entity is flung millennia into the future, then promptly dragged back to an instant mere moments after the formation of reality, before being slammed into the depths of the earth approximately thirty-four minutes after the passing of an age. Deals minor damage, but deprives an entity of a chance to act in the turn inflicted.
Ancestral:
Agreement Inapposite: Antares glows with magenta energies, and barters his essence with that of a selected being, granting both the Contracted status effect for three turns. During this time, any damage dealt to Antares will assail the contracted being instead, and vice versa.
Cthk'aryvtian Servitude: Antares becomes an Avatar of the Great Cthk'aryvt. In this state, retaliatory damage is dealt to all aggressors in a quantity precisely half of what was granted, and all assaults Antares attempts afflict Afterimage on the struck entity for one turn.

Algor Mortis: Upon death, the essence of Antares is torn apart by the Breach, and consumed. This fully punches the intended hole into reality, leading to a general consumption of heat energy within a rather large distance. Regardless, the rift will thusly be primed for 9.

[III] Aeon Core: READY TO USE. Wearer: ???

A blob of magetear sealed within an armored sphere of warded corotite and alchemically-treated glass. One can channel the potent magetear within to call forth a spectral version of Valedrius, the blade of Antares, for a brief time. The blade, once set to anything resembling life, immediately scars it for time immemorial, inflicting the being in question with Afterimage for two turns, and dealing major damage.