From what I have on the Transcripts, Magic of this level starts out by effecting (Well as stated with in the first 'step') as more or less the wind up. Magi are able to feel the building of energy. (Steps representing the times he took a step)

Step 2: Starts out as a Silence, stopping the formation of new Magic or spells.

Step 3: Acts as a massive dispell, causing enchantments or things that have enchantments to stop, not removing just stopping them from being used/activated while the Second Step STOPs the reactivation of said enchantment (because the spell that was used to forge it).

Step 4: Now this is more advanced level on it, but it starts to effect the mind, as most would of assumed. Causing you to have blank stops (temporally of course) when it comes to knowledge. Just Knowledge related to spells, not full on mental memory...brain surgeon we are not. 

Step 5: This is what made this spell a rather high level spell: It starts to effect the soul, never stopping one from ever causing/using magic but rather, stopping the soul (As Thin explained) from acting in a way to make more Mana/acting as a point from which Magic is formed before taking its Physical/Ethereal from.

This would reach across all levels of know magic. Its basicly a big old EMP for Art...of course it isn't something that can be sustained for extended periods of time with out effects on the caster meaning drop it once, let it ride till a timer runs out. Then its done. Stronger the caster, longer the timer before it starts to show effects on its caster.

Hope this helped.