What is the Manual of the Modrossus?

Question

Recently, when trying to find bits of lore for characters in a game I'm running set in the Nerian Nexus, former home to Master Mage Adrian Eldrich, I ran into a mention of a "Manual of the Modrossus" in the Power Profiles book. At the time, I didn't find an immediate explanation, and so instead went with the "Medallion of the Modrossus", which did have defined status in the Gadget Guides book and in one of the later Netherwar adventures. Now, I'm kind of curious. Is there any definition of this Manual? Is it just meant to be a reference to the "Magic of the Modrossus" mentioned in the Power Profiles?

The legendary Manual and Medallion of the Modrossus are entrusted to Earth’s Master Mage.

FWIW, the Medallion of the Modrossus from Gadget Guides:

MEDALLION OF THE MODROSSUS

This silver clasp bearing the Mark of the Modrossus (a circle within a triangle) is part of the regalia of Earth’s Master Mage. The Medallion is a powerful talisman of light and truth against the forces of darkness and chaos. When willed, it emits a pure blue-white light able to blind, read thoughts, or banish creatures of supernatural evil. Its power is limited, however, by the arcane knowledge and skill of its wielder, who must possess the Magic power (that is, an array of Alternate Effects with a magic descriptor). See the sample Magic power in Chapter 6 of the Hero’s Handbook.

Medallion of the Modrossus: three Dynamic Alternate Effects: Ranged Affliction (blinding light; Impaired, Disabled, Unaware), Cumulative, Limited to Vision; Mind Reading; Nullify Summon Supernatural Creatures, Perception Range), Removable (–1 point) • 5 points

Answer 1

On Mutants and Masterminds Monday, Steve started explaining it was a "powerful mystical artifact", but then Crystal interjected that it was explained in the 2e Book of Magic

Manual of the Modrossus

This legendary tome of arcane lore is the most powerful collection of spells and rituals for good ever known. Its origins are shrouded in antiquity, but it has passed through the hands of most (if not all) of Earth’s Master Mages over the millennia.

The Manual is a heavy book of ancient vellum pages covered with illuminated script in a variety of languages, many of them completely unknown to modern scholars. It is bound in deep blue leather, said to be dragon-hide, with brass cover-caps, a locking clasp, and the sign of the Modrossus—a circle inside a triangle—on the cover in brass. In spite of its apparent age, the Manual is actually far older and virtually indestructible by mortal means.

Among its unusual properties is the fact that the last page of the book is always blank; there always appears to be space to write new text, and many Master Mages have added to the Manual over the years.

The Manual was lost for a time in the late 19th and early 20th centuries, claimed by the Cult of Kar’Kradas after the untimely death of Master Mage Violet Pennyworth. Adrian Eldrich later reclaimed it from the Cult’s vile clutches, and it now resides in a warded vault in his sanctum in Freedom City.