I put this on the Diablo3 forums, but I figured I'd share it here too:
This build is going to have the unique ability to be able to completely immobilize a group of enemies for 8 seconds out of every 17. Instead of a Frost Nova for 3 seconds out of every 10.2 seconds, this is like an 8 second Frost Nova. Your spell sequence will be:
Teleport to middle of group --> Arcane Hydra --> Slow Time --> Reversal --> Disintegrate to heart's content
Reasoning: I teleport to place the Slow Time exactly where I want, place an Arcane Hydra, and then Reverse out. With temporal flux, the Arcane Hydra's AOE arcane and three heads will push the movement speed reduction to 110% for everything inside the Slow Time. Once inside of the Slow Time, ranged targets will have their projectiles speed reduced by 90% effectively immobilizing them completely.
This immobilization will cost 70 AP to cast. To offset this, I use Chain Lightning with Prodigy for some serious AP regen on top of Energy Armor with Energy Tap. Energy Tap also helps to off set the hits I'll take on the way in to drop off the Slow Time and Hydra. While inside of the Slow Time, Disintegrate with Volatility will do some ridiculous damage. When I am out of AP to cast Disintegrate, the hydras will keep up the 110% slow while I regen with Chain Lightning.
I use Chain Lightning in order to diversify my elements. Also, Disintegrate and Chain Lightning allow me to target and take out ranged enemies in groups or single target without worrying about melee getting in the way.
The last bit of logic here is against enemies where I am drawn in to them. I can still cast Slow Time and Hydra, but I can stay inside the bubble and use it as a barrier from things coming in. While inside, I can either use Disintegrate or Chain Lightning to AOE or single target.
Lastly, Evocation let's me use the combo as often as possible.