It took me a day to figure this out, maybe it will help someone. Other builds focusing on age manipulation or matter were totally a joke (as in the minotaur beat the crap out of it). This build killed him (in sweet vengeance) without a scratch. I had been doing the maze right after all the low level dungeons and so never knew how good or how bad my build was until meeting the minotaur. This was around 13-14 level.
Time skipping him and locking out his healing abilities, as well as keeping him in one little area of the battlefield with wormhole and gravity, eventually allowed me to echoes him significantly. I also used redux to double slow. The second point in dimensional step is so I can cross the slow field when enemies reach one side. I had one close call at the end where he killed one of my afterimages from haste (shortly after confusing), then blinded me. The coup de grace was a repulsion blast while blinded. So, so, satisfying.
Anyways, this is by far the strongest paradox mage build I've had (at these levels). The key is time travel, obviously. Since then I've added temporal reprieve 5/5 (amaaaaaazing) and spacetime mastery (for endless time skips).