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Ars Magica 2 Information
As for modifiers, a single aspect of a spell can be modified three times per stage. What this means is that if you have modifiers that change multiple parts of a spell, they may lock out other ones that modify the same stats if the total stat modifier for the shape is equal to three.
Occulus tabOffense, Defense, Utility

Modifiers are a part of Ars Magica 2's spell grammar. They are used to change a spell's proprieties, such as increasing the damage of a Projectile-Lightning Damage spell via the Damage modifier, or the duration of a Self-Regeneration spell via the Duration modifier.

Modifiers can be found with a diamond border in the Occulus. Depending on the modifiers's enhancement, it's categorized into either the Occulus's Offense, Defense, or Utility tab. An additional aesthetic modifier (Colour) is found in the Occulus's Talent tab.

Spell Grammar

Unlike spell Components a single spell may contain up to three copies of a single modifier, allowing a spells such as Self-Flight-Duration-Duration-Duration to be fully possible.

Additionally, more than one Components in a single spell can be affected by the same modifier. Eg: An Flight-Haste-Duration spell will have both the time limit of Flight and Haste increased.