I'm posting this here so I don't forget. There are a number of spells that are literally powered by level.
If they are powered by Wisdom or Will, they are just a bonus check as far as I can tell.
Here's the list:
Sleep (it is most apparent via the Slumber Sword)
Hold
Pin
Weak/Tornado
Odin - only spell to be powered solely by level, since the "Summon" or Wisdom part of the spell has a hit rate of 0%
My only guess is that the enemy's version of Paralyze and Sleep attacks are built on the same principle.
I believe it also includes normal physical enemy attacks that inflict those status... but I could be wrong.
The basic check is like this...
rand (0, Target's Level) < rand (0, Caster's Level)