If you are using Circle Magic, here are some nice little batteries (I.E. they're first level characters who give you 16 spell levels.)
Silverbrow Human Warmage 1
Feats: Eldritch Corruption, Heighten Spell, Earth Sense, and Earth Spell. Requires 2 flaws.
This is a nice first level follower for any RWoT, because you can get 80 spell levels out of 5 of them, instead of the 35 you'd get normally.
A higher level version (as in 6th level) can store 106 spell levels. Each.
Silverbrow Human Warmage 6
Feats: 1st: Eldritch Corruption, Heighten Spell, Earth Sense, Earth Spell. 3rd: Easy Metamagic (Heighten Spell). 6th: Practical Metamagic (Heighten Spell)
Basically, freely heighten all spells by 3, and then use Eldritch Corruption to raise three 6th level spells to 8th level.
Effectively, with a circle of 5 of these guys, you can generate 530 spell levels. That's enough to raise Mr. 10th level Thayan Wizard to Cl 40, and give him the ability to raise 25 CANTRIPS to 20th level.
At level 15, Mr. Thayan Wizard has 10 of these guys. Can you say 1060 spell levels?
Obviously, there are probably far more efficient ways to use Circle Magic, but with 5 6th level characters?
Yeah, you just nuked Paris.