u/Know_Yog_Sothoth

Complete speculation:
[[Arcanis the Omnipotent]] is an absolute ringer for Jace for reality fracture. A blue mage capable of teleporting to a space you cannot follow (returning to hand is a return to the meditation realm) who can give you secret knowledge (draw 3), who (per flavor text) has journeyed far and has returned to “make sure none shall follow.” His name is cool but basically just means “wizard guy.”
Further speculation would be why is he there in the pits? Kamahl’s sword is made of a powerful artifact made of Urza’s staff, the nexus event of the creation of Karona (a WUBRG powerhouse), and at least one powerful planeswalker (Jeska). Plus Mirari shenanigans which is another energy battery and I believe deeply connected to Mirrodin.