For those who may be wondering, if you want to learn a spell your rank must reflect the level of the spell. For example, if you wish to learn a level 80 spell, you must be ranked Very Strong to do so.

Magical Power Scale

Destructive spells are often categorized by their power. In addition, more destructive spells are harder to learn. A Magic Blast spell, Which is learned under level 1-10, will be less powerful than a Magic Blast learned under level 11-20. If you hit a level 10 character with a level 1-10 Magic Blast, depending on your magic level, the blast may be fatal. However, if you strike a level 23 character with that same blast, it would (at best) leave a very nasty burn.