Mana Wastes
Conjuration - Terrain
Mana
Arcane level 1 or Dark level 1
Mana cost 5 (based on Mana Shard cost, increased due to Terrain type and can impact multiple objects)
Objects that channel in this zone gain Channeling -1
I don't think this would be popular as lowered Channeling would generally tend to slow the game down, but could help with a Mana denial strategy (which needs to be a valid strategy IMO), and gives the Wizard an in-school terrain.