I told that before, and it is confirmed and this is un-documented combo. You are right, it's pretty viable, and its undocumented power of Solas/Quiz rift mage. It works wonders with templar/sleep rogues in party. I said in other threads that Cass+Cole+Solas = nightmare stunlock, and because panic provides auto-crit for Mercy Killing perk rogues, this comp screams for double rogue comp. Generally tempest one. Templar + Rift Mage + Assasin + Tempest is nightmare panic terror party :V
Nightmare Detonators:
Templar dispel spell + damage
At least 3 (up to 5) AOE spells from Rift/Spirit/Lightning/Cold trees.
Sleep Generators:
Shocked + Stagger + Weakness combo effects from Rift Mage and Templar abilities -there are many, starting from cripple and Templar stuff , Templar stagger eq and shock/stagger from lightning and rift spells.
Knock Bomb from Assasin
2x Knock Poder cones ,one of which is enhcanced or with LF or with FF from Tempest.
Frost Generators:
Winter Grasp.
Barrier Explosions.
Tempest Frost Flask.
Rupture Generators:
Impact abilities of Templar and Fist from Rift, on sleeping targets.
Sharrerers:
2 x Twin Blades of Tempest and Assasin
2 x Shadow Strike of Tempest and Assasin
Deathblow from Assasin
Fist of Rift Mage.
Lunge from SnB tree of Templar build.