PosChengBand - Curse Effects?

[CyclopsSlayer]

There are three effects I keep seeing I can guess at, but am not sure what the effects exactly are.

-Spell Capacity
-Spell Prowess
-Spell Power

I can guess that it is spells that can be learned, failure chance, and maybe mana costs? But have no idea for sure.

[Bostock]

Spell Capacity is actually mana. Not sure about the rest.