[Sir_Dr_D]

Yes lvl 9 spells should be powerfull, but Arcane Nexus makes all other 9th level spells seem small.

Once you case Arcane Nexus, you would have the gems to dispel any other global enchantment out there, and you control all the globals. Arcane Nexus would be balanced with spells utterdark, or Natures Bounty, if the gems that you get from Arcane Nexus weren't the same ones you can use to dispel other enchanments.