The Shard of Hatred
Vulcanos of Verditius was specialized in metal-crafting, with magical arts surpassing many of his bretheren. However, after a terrible assault by rivals on his boon companion and friend, Incarnos of Flambeaux, he spent years studying Mentem to help defend him. After a particularly... enlightening Twilight vision, Vulcanos decided to push his limits and combine the two disparate foci. He found that there were few real reasons to use this spell instead a normal Creo Terram conjured blade. But he still used the spell all the time.
Design notes: This spell was designed under the assumption that a blade created from hatred with Muto Terram will have no real special effects. This is because by the rules, the blade would have no special effects. If this spell was actually made in a saga I was adjudicating, I would give it some neat abilities by default, probably the listed Minor Benefit.
The Shard of Hatred (Muto Mentem [Terram])
R: Touch, D: Diameter, T: Part
As the spell is cast, a long blade of shimmering red-hued sword appears in the target's hand. This blade is the target's anger and rage given solid, sharp form, and if the target's hands are not closed, it will fall to the ground at their feet. While this spell is active, the target gets the Personality trait Angry -3, or an appropraite trait of theirs lowers by 3. Due to the designer's sigil, the forming blade is accompanied by a sound like breaking glass. This sword is well-made, but otherwise has no special traits beyond a normal blade, and if it breaks, it flows back into its original target, ending the spell.
(Base 25, +1 Touch, +1 Diameter, +1 part)
Side Effects table (1d10)
1 Exaggerated Sigil: In addition to the breaking glass sound when the blade forms, every time it is swept around a tinkling sound like falling glass shards rings out, louder or quieter based on how aggressively the blade was swung.
2-3 Minor Flaw: If the target has the Angry (or matching) personality trait at +3 or greater, the summoned sword is a long sword. If their Angry (or equivalent) personality trait is -3 or less, the blade summoned is a dagger. Otherwise, it is a short sword.
4-5 Minor Side Effect: The blade, formed of a fraction of a mind, can be wielded by a ghost or spirit of the Mentem form.
6 Minor Benefit: The blade's sharpness is affected by the anger of the target. The conjured blade's damage is increased by the target's original Angry Personality trait.
7 Major Flaw: After the spell duration ends, the target of the spell has trouble remembering what happened during it, as parts of their memory are crystalized. They must make an Intelligence + Concentration roll of ease factor 9 to remember the time where their mind was split. Furthermore, if the blade breaks, they lose consciousness.
8 Major Side Effect: if the target wields the conjured blade themselves, each of their Personality traits are doubled instead of the normal effects on their Personality traits.
9 Major Benefit: If the target is wielding the blade, they gain control over their emotions while it is held in hand. They can allow their other emotions to flow into the blade (appearing as decorations upon the otherwise simple blade and pommel) which will allow them to alter their own personality traits towards +0 with but a moment's concentration.
10 Fatal Flaw: Creating the sword draws way more out of the target than actually intended, and out of the caster of the spell as well. Both caster and target gain the Flaw Simple-Minded for the duration, though only the target gets the Angry -3 Personality trait.