So, let's see, we already have a slowing/tripping effect aura..

I don't like dealing with ability damage. While good in theory, I would rather see something like an equivalent penalty, such as..

Spellweaver's Lament: All enemies within 30 feet attempting to cast a spell or spell-like ability or manifest a power or psi-like ability must make a Concentration check as if they were taking ongoing damage equal to double your Aura bonus. Failing this check causes the attempt to fail, but does not expend the resources.

Weakening Cry: When you project this aura, choose a number between 0 and your aura bonus. All enemies within 60 feet take a penalty to melee attacks equal to this number, and take a penalty to melee damage equal to your aura bonus minus the previous penalty. Both penalties added together should equal your aura bonus.

I'm going for non-traditional effects here. Any other ideas that are interesting but not overpowered, given that this IS an always-on constant effect?