With the tied vote of Treshure's modification to Fi' lore and other comments, a revision and/or clarification of Tempered Fi' was requested. It is rendered below.
The Tempering of Souls
The Fi’ who so wander this world are not those who had done so in the past. The ancient art, riddled in mystery and ritual had been lost to time— lost to the gradual dispersion of the once proud Elibar’acal. And yet, the Golden Veil cracks. There was wealth to be found in this realm of Vailor, and not wealth of jewels… But wealth sealed within a Golden Tomb.
Comparisons
As compared to Untempered Fi', Tempered Fi' is less efficient at draining magic (as established in the original Tempered Fi' lore). While an Untempered Fi' mage, who notably specializes in their magic type, and does have a soul directly latched to them, a Tempered Fi' mage is less specialized and does not have a soul directly latched to them.
The notion one needs to "remove the Holy nature" of Tempered Fi' remains unfounded. The "Holy" interpretation is an IC one. Just like "Dark Magic" is also an IC interpretation.
To clarify Tempered Fi' lore, these practitioners still suffer the Schizophrenic-like tendencies of their Untempered Fi' kindred. However, they are more muted— given the soul is not attached to them directly. No where does this say this is absent.
To summon from undisclosed lore— a Tempered Fi' mage can be disabled by the capture of their Orb. It will dissipate when too far from them. Another sacrifice is required to reforge the Orb. An Untempered Mage can not be disabled.
An untempered Fi' mage can still learn both subtypes.
A Tempered Fi mage may construct a soul-library (a device with which to store an Orb without it dissipating in their absence).
A Tempered Fi' mage is less physically strong than a normal individual. They are stronger than mages. If one imagines a mage as 50% as strong as a regular person (in terms of physical strength) a Fi' mage is 75% as strong.
A tempered Fi' or untempered Fi' user can not sense dark magics. This is not read anywhere on the lore, and was already a settled matter. Just as a Cleric, Ascended, or Shade can't sense one another.
Soul afflictions can still be rended with OOC permission.
Enchanting still makes you ill.
Weapon forging is removed. It was never a role-played element and, upon initial acceptance of the original lore, was removed for it lacked lore. This has never been a part of Tempered Fi'. The only weapon forging is for the ritual. If it is to be made, lore will be written. As always.
It is also worth noting the revision proposed by Treshure significantly empowered, rather than Reduced Fi'. Given it removed the exceptions of the various magics which, over time, wrote their lore to exempt themselves from "Acaele" Fi'. Consequentially, an Untempered Fi' mage under Treshure's lore is able, without sacrifice of power, to simply learn both subtypes of Fi' and drain more efficiently all magics than a Tempered Fi' mage— their only sacrifice being physical strength— which is irrelevant as they can already drain the energies of a mage and stab them to death even if they are not summoning magic.